feat(#90): IMP-56 u1-u19 catch-up before final close (post-u20 push fix)

u1: text_overrides axis in user_overrides_io
u2: structure_overrides axis in user_overrides_io
u3: vite allowlist for new endpoints
u4: text_override_resolver
u5: Step 12 text_overrides apply in phase_z2_pipeline
u6: structure_override_resolver
u7: text_path_stamper
u8: SlideCanvas text-edit capture
u9: SlideCanvas structure-edit overlay
u10: userOverridesApi service extension
u11: designAgent types extension
u12: slidePlanUtils restore
u13: user_overrides endpoint tests
u14: user_overrides restore tests
u15: pipeline fallback tests
u16: edit-mode state + gating tests
u17: slide_base print mode CSS
u18: /api/connect endpoint (vite)
u19: /api/export endpoint (vite)

Recovery scope: 29 files (12 modified + 17 new). u20 already pushed in
9439575; this commit lands u1-u19 that were authored but not committed
before #90 was externally closed.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Front/client/src/components/SlideCanvas.tsx

@@ -28,7 +28,12 @@ import {
   crossedDragThreshold,
   type ImageDragDirection,
 } from "./slideCanvasDragMath";
-import type { ImageOverridesOverride } from "../services/userOverridesApi";
+import type {
+  ImageOverridesOverride,
+  StructureOverridesOverride,
+  StructureOverridePerZone,
+} from "../services/userOverridesApi";
+import StructureEditOverlay from "./StructureEditOverlay";
 
 interface SlideCanvasProps {
   slidePlan: SlidePlan | null;
@@ -73,11 +78,112 @@ interface SlideCanvasProps {
     imageId: string,
     geometry: { x: number; y: number; w: number; h: number }
   ) => void;
+  /** IMP-90 (#90) u13 — focusout-emitted capture; u15 debounces + PUTs. */
+  onTextEdit?: (capture: TextEditCapture) => void;
+  /** IMP-90 (#90) u14 — persisted structure overrides per zone
+   *  (slot_order + hidden_slots). When `editMode === "structure"` the
+   *  StructureEditOverlay reads from this to render the current state. */
+  structureOverrides?: StructureOverridesOverride;
+  /** IMP-90 (#90) u14 — emitted whenever the user reorders or hides a
+   *  slot in structure-mode. u15 will debounce + PUT to /api/user-
+   *  overrides; u14 only exposes the capture. SCOPE LOCK: inner shape is
+   *  `{slot_order, hidden_slots}` only (frame swap stays on `frames` axis). */
+  onStructureEdit?: (zoneId: string, capture: StructureOverridePerZone) => void;
 }
 
 const SLIDE_W = 1280;
 const SLIDE_H = 720;
 
+// IMP-90 (#90) u11 — discriminated edit mode. Replaces the prior single
+// `isEditMode` boolean. u11 introduces the enum + the toolbar UI surface;
+// gesture gating (text contentEditable vs structure reorder vs image-zone
+// drag/resize) stays unified behind `isEditMode = editMode !== 'off'` so
+// existing behavior is preserved byte-identical. u12 will discriminate the
+// gestures per mode (mutually exclusive). The 'off' state is the no-edit
+// baseline; 'image-zone' bundles image edit (#79) + zone resize (#81)
+// because both are pointer-driven canvas gestures on slide geometry.
+export type EditMode = "off" | "text" | "structure" | "image-zone";
+export const EDIT_MODES: ReadonlyArray<EditMode> = ["text", "structure", "image-zone"];
+/** Pure helper — given the current edit mode and the user's requested mode,
+ *  return the next mode. Clicking the active mode toggles back to 'off';
+ *  clicking a different mode switches; explicit 'off' always exits. */
+export function nextEditMode(current: EditMode, requested: EditMode): EditMode {
+  if (requested === "off") return "off";
+  return current === requested ? "off" : requested;
+}
+
+// IMP-90 (#90) u12 — per-mode gesture gating. Pure helper deriving the
+// boolean gates that drive SlideCanvas's useEffect branches (designMode
+// + iframe-side image click listener) and JSX conditionals (iframe
+// pointer-events, zone resize/drag affordances, image overlay). The
+// mapping enforces the mutually-exclusive contract from the issue body:
+//   text       -> contentEditable + iframe pointer-events:auto only.
+//   structure  -> nothing here; u14 will plant the structure overlay.
+//   image-zone -> zone resize/drag + image overlay; iframe pe:auto so
+//                 in-iframe user-content images can be click-selected.
+//   off        -> every gate false (baseline).
+// pendingLayout fully suppresses every gate — mirrors the existing
+// useEffect (line ~248) that forces editMode='off' on pendingLayout
+// entry. The helper still defensively returns all-false so a stray
+// pendingLayout=true with a non-'off' editMode never leaks gestures.
+export interface EditModeGates {
+  textEditing: boolean;
+  imageSelection: boolean;
+  iframePointerAuto: boolean;
+  zoneGestures: boolean;
+  imageOverlay: boolean;
+}
+export function computeEditModeGates(
+  editMode: EditMode,
+  isPendingLayout: boolean
+): EditModeGates {
+  if (isPendingLayout) {
+    return {
+      textEditing: false,
+      imageSelection: false,
+      iframePointerAuto: false,
+      zoneGestures: false,
+      imageOverlay: false,
+    };
+  }
+  return {
+    textEditing: editMode === "text",
+    imageSelection: editMode === "image-zone",
+    iframePointerAuto: editMode === "text" || editMode === "image-zone",
+    zoneGestures: editMode === "image-zone",
+    imageOverlay: editMode === "image-zone",
+  };
+}
+
+// IMP-90 (#90) u13 — pure helper resolving a contentEditable focusout
+// target into (zoneId, textPath, value). data-text-path stamped by u8 at
+// Step 13; .zone[data-zone-position] from Phase Z slide-base. Non-stamped
+// targets return null so capture silently skips. u15 will debounce + PUT.
+export interface TextEditCaptureTarget {
+  closest(selector: string): TextEditCaptureTarget | null;
+  getAttribute(name: string): string | null;
+  textContent: string | null;
+}
+export interface TextEditCapture {
+  zoneId: string;
+  textPath: string;
+  value: string;
+}
+export function deriveTextEditCapture(
+  target: TextEditCaptureTarget | null
+): TextEditCapture | null {
+  if (!target) return null;
+  const lineEl = target.closest("[data-text-path]");
+  if (!lineEl) return null;
+  const textPath = lineEl.getAttribute("data-text-path");
+  if (!textPath) return null;
+  const zoneEl = lineEl.closest(".zone[data-zone-position]");
+  if (!zoneEl) return null;
+  const zoneId = zoneEl.getAttribute("data-zone-position");
+  if (!zoneId) return null;
+  return { zoneId, textPath, value: (lineEl.textContent ?? "").trim() };
+}
+
 export default function SlideCanvas({
   slidePlan,
   userSelection,
@@ -93,6 +199,9 @@ export default function SlideCanvas({
   onZoneResize,
   imageOverrides,
   onImageResize,
+  onTextEdit,
+  structureOverrides,
+  onStructureEdit,
 }: SlideCanvasProps) {
   const containerRef = useRef<HTMLDivElement>(null);
   const [scale, setScale] = useState(1);
@@ -135,7 +244,15 @@ export default function SlideCanvas({
   // HTML 편집 모드 — 글벗 패턴 (designMode + contentEditable + outline CSS) 차용.
   // 활성 시 iframe 안 텍스트 element 직접 클릭하여 수정 가능. backend 반영은 별 작업.
   // pendingLayout 과 배타적 (충돌 방지).
-  const [isEditMode, setIsEditMode] = useState(false);
+  // IMP-90 (#90) u11 — `editMode` enum replaces the prior boolean. The
+  // `isEditMode` shim is kept ONLY for the pendingLayout coupling +
+  // zone-wrapper visual cues (border / hover / selected styling) that
+  // fire whenever any edit mode is active. u12 routes gesture-activating
+  // gates through `editGates` so text / structure / image-zone gestures
+  // are mutually exclusive.
+  const [editMode, setEditMode] = useState<EditMode>("off");
+  const isEditMode = editMode !== "off";
+  const editGates = computeEditModeGates(editMode, !!isPendingLayout);
   const iframeRef = useRef<HTMLIFrameElement>(null);
 
   // 편집 모드 toggle 시 iframe contentDocument 에 글벗 패턴 적용 / 해제.
@@ -159,11 +276,22 @@ export default function SlideCanvas({
 
     const editableTags = ["DIV", "P", "H1", "H2", "H3", "H4", "SPAN", "LI", "TD", "TH", "FIGCAPTION"];
     let inputHandler: ((e: Event) => void) | null = null;
+    // IMP-90 (#90) u13 — focusout (= bubbling blur) emits one capture per
+    // finished line edit; u15 will debounce + PUT.
+    let textEditCaptureHandler: ((e: Event) => void) | null = null;
     // IMP-51 (#79) u8 — user-content image click listeners installed
     // inside the iframe contentDocument. Tracked here so the cleanup
     // callback can remove them when edit mode exits (or iframe reloads).
     const imageClickBindings: Array<{ el: HTMLImageElement; handler: (e: Event) => void; prevCursor: string; prevOutline: string }> = [];
-    if (isEditMode) {
+
+    // IMP-90 (#90) u12 — text-editing gate: only the 'text' editMode
+    // turns designMode on + makes the editable tags contentEditable.
+    // The else branch tears the prior state down so leaving text mode
+    // (to structure / image-zone / off) immediately disables in-place
+    // text editing — required for mutual exclusivity vs the image-zone
+    // overlay's drag/resize gestures (a contentEditable cursor would
+    // otherwise be placed by every image click).
+    if (editGates.textEditing) {
       doc.designMode = "on";
       doc.querySelectorAll(".slide *").forEach((el) => {
         if (editableTags.includes((el as HTMLElement).tagName)) {
@@ -176,11 +304,28 @@ export default function SlideCanvas({
       };
       doc.addEventListener("input", inputHandler);
 
-      // IMP-51 (#79) u8 — wire click → selectedImageId on every stamped
-      // user-content image. Selector mirrors USER_CONTENT_IMAGE_SELECTOR
-      // in src/image_id_stamper.py (+ requires data-image-id which the
-      // stamper always emits). Decorative / frame imgs lacking the role
-      // attribute are intentionally NOT clickable here.
+      textEditCaptureHandler = (ev: Event) => {
+        const cap = deriveTextEditCapture(
+          ev.target as unknown as TextEditCaptureTarget | null
+        );
+        if (cap) onTextEdit?.(cap);
+      };
+      doc.addEventListener("focusout", textEditCaptureHandler);
+    } else {
+      doc.designMode = "off";
+      doc.querySelectorAll("[contenteditable]").forEach((el) => {
+        (el as HTMLElement).removeAttribute("contenteditable");
+      });
+    }
+
+    // IMP-90 (#90) u12 — image-selection gate: only the 'image-zone'
+    // editMode wires the in-iframe user-content image click → selection.
+    // Selector mirrors USER_CONTENT_IMAGE_SELECTOR in image_id_stamper.py
+    // (requires data-image-id which the stamper always emits). Decorative
+    // / frame imgs lacking the role attribute are NOT clickable. The
+    // else branch clears `selectedImageId` so the React-side overlay
+    // never lingers on a non-image-zone edit mode.
+    if (editGates.imageSelection) {
       const imgEls = doc.querySelectorAll<HTMLImageElement>(
         '.slide img[data-image-role="user-content"][data-image-id]'
       );
@@ -200,12 +345,6 @@ export default function SlideCanvas({
         imageClickBindings.push({ el: imgEl, handler, prevCursor, prevOutline });
       });
     } else {
-      doc.designMode = "off";
-      doc.querySelectorAll("[contenteditable]").forEach((el) => {
-        (el as HTMLElement).removeAttribute("contenteditable");
-      });
-      // edit-mode exit also clears stale image selection so the handle
-      // overlay never lingers on a non-editable iframe.
       setSelectedImageId(null);
     }
 
@@ -213,19 +352,60 @@ export default function SlideCanvas({
       if (inputHandler && doc) {
         doc.removeEventListener("input", inputHandler);
       }
+      if (textEditCaptureHandler && doc) {
+        doc.removeEventListener("focusout", textEditCaptureHandler);
+      }
       imageClickBindings.forEach(({ el, handler, prevCursor, prevOutline }) => {
         el.removeEventListener("click", handler);
         el.style.cursor = prevCursor;
         el.style.outline = prevOutline;
       });
     };
-  }, [isEditMode, finalHtmlUrl, onContentEdit]);
+  }, [editGates.textEditing, editGates.imageSelection, finalHtmlUrl, onContentEdit, onTextEdit]);
 
   // pendingLayout 진입 시 편집 모드 자동 OFF (충돌 방지).
   useEffect(() => {
-    if (isPendingLayout && isEditMode) setIsEditMode(false);
+    if (isPendingLayout && isEditMode) setEditMode("off");
   }, [isPendingLayout, isEditMode]);
 
+  // IMP-90 (#90) u14 — discover slot keys per zone for the structure
+  // overlay. Source = iframe DOM `data-text-path="{slot_key}.{line_index}"`
+  // attributes stamped by u8 (`src/text_path_stamper.py`). Unique slot_key
+  // prefixes per `.zone[data-zone-position]` form the overlay's slot list.
+  // Discovery runs only when entering structure mode (and resets on exit
+  // or iframe reload) so off / text / image-zone modes never pay this
+  // traversal cost.
+  const [slotKeysByZone, setSlotKeysByZone] = useState<
+    Record<string, string[]>
+  >({});
+  useEffect(() => {
+    if (editMode !== "structure" || isPendingLayout) {
+      setSlotKeysByZone({});
+      return;
+    }
+    const doc = iframeRef.current?.contentDocument;
+    if (!doc) return;
+    const next: Record<string, string[]> = {};
+    doc.querySelectorAll(".zone[data-zone-position]").forEach((zEl) => {
+      const zoneId = (zEl as HTMLElement).getAttribute("data-zone-position");
+      if (!zoneId) return;
+      const seen = new Set<string>();
+      const keys: string[] = [];
+      zEl.querySelectorAll("[data-text-path]").forEach((lineEl) => {
+        const path = (lineEl as HTMLElement).getAttribute("data-text-path");
+        if (!path) return;
+        const lastDot = path.lastIndexOf(".");
+        const slotKey = lastDot > 0 ? path.slice(0, lastDot) : path;
+        if (slotKey && !seen.has(slotKey)) {
+          seen.add(slotKey);
+          keys.push(slotKey);
+        }
+      });
+      next[zoneId] = keys;
+    });
+    setSlotKeysByZone(next);
+  }, [editMode, isPendingLayout, finalHtmlUrl]);
+
   // finalHtmlUrl 이 바뀌면 (= 다른 run / 재실행) stale 측정값 reset.
   // 새 iframe 의 onLoad 가 발화하면서 measuredZones 다시 채움.
   useEffect(() => {
@@ -332,28 +512,50 @@ export default function SlideCanvas({
             </button>
           )}
 
-          {/* 편집 모드 toggle 버튼 — normal mode + final.html 있을 때만.
-              글벗 패턴 차용 — designMode + contentEditable. backend 반영은 별 작업. */}
+          {/* IMP-90 (#90) u11 — discriminated edit-mode toolbar.
+              Replaces the prior single ✏ toggle. Three modes (text /
+              structure / image-zone) are mutually exclusive; clicking the
+              active mode toggles back to 'off'. Gesture gating per mode is
+              u12 — u11 only plants the state + UI surface, so all three
+              modes currently share the same `isEditMode` shim behavior. */}
           {!isPendingLayout && finalHtmlUrl && (
+            <div
+              data-testid="edit-mode-toolbar"
+              className="absolute top-2 right-2 z-30 flex gap-1"
+              style={{ pointerEvents: "auto" }}
+            >
+              {EDIT_MODES.map((mode) => {
+                const active = editMode === mode;
+                const label =
+                  mode === "text" ? "✏ 텍스트" : mode === "structure" ? "▦ 구조" : "🖼 이미지/존";
+                const title =
+                  mode === "text"
+                    ? "텍스트 편집 — 텍스트 클릭하여 직접 수정"
+                    : mode === "structure"
+                    ? "구조 편집 — slot 순서 / 숨김 변경 (u14 펜딩)"
+                    : "이미지/존 편집 — 이미지 드래그·리사이즈 + 존 리사이즈";
+                return (
                   <button
+                    key={mode}
+                    type="button"
+                    data-testid={`edit-mode-${mode}`}
+                    aria-pressed={active}
                     onClick={(e) => {
                       e.stopPropagation();
-                setIsEditMode((p) => !p);
+                      setEditMode((prev) => nextEditMode(prev, mode));
                     }}
-              className={`absolute top-2 right-2 z-30 text-[10px] font-bold uppercase tracking-tighter px-2.5 py-1 rounded shadow transition ${
-                isEditMode
+                    className={`text-[10px] font-bold uppercase tracking-tighter px-2.5 py-1 rounded shadow transition ${
+                      active
                         ? "bg-emerald-500 text-white hover:bg-emerald-600 ring-2 ring-emerald-200"
                         : "bg-white text-slate-700 hover:bg-slate-100 border border-slate-200"
                     }`}
-              style={{ pointerEvents: "auto" }}
-              title={
-                isEditMode
-                  ? "편집 모드 — 텍스트 클릭하여 수정. 다시 클릭하여 종료. (변경은 frontend 만, backend 반영 미구현)"
-                  : "텍스트 직접 편집 모드 진입"
-              }
+                    title={title}
                   >
-              {isEditMode ? "✏ 편집 중 (클릭 종료)" : "✏ 편집"}
+                    {label}
                   </button>
+                );
+              })}
+            </div>
           )}
 
           <div
@@ -375,7 +577,13 @@ export default function SlideCanvas({
               className="w-full h-full border-0 block"
               scrolling="no"
               sandbox="allow-same-origin allow-scripts"
-              style={{ pointerEvents: isEditMode ? "auto" : "none" }}
+              // IMP-90 (#90) u12 — iframe pointer-events gate. 'text' needs
+              // pe:auto so the user can click into text fields; 'image-zone'
+              // needs pe:auto so user-content image clicks can reach the
+              // in-iframe click handler that drives `selectedImageId`.
+              // 'structure' and 'off' keep pe:none — structure has no
+              // in-iframe gesture (u14 will overlay React-side controls).
+              style={{ pointerEvents: editGates.iframePointerAuto ? "auto" : "none" }}
               onLoad={(e) => {
                 // IMP-14 (Step 13 A-4) — embedded vs standalone CSS reset 은 backend
                 // slide_base.html 가 `?embedded=1` query 로 소유. frontend 가 더 이상
@@ -564,9 +772,11 @@ export default function SlideCanvas({
             const makeResizeHandler = (
               direction: ResizeDir
             ) => (ev: React.MouseEvent<HTMLDivElement>) => {
-              // resize 는 pendingLayout OR 편집 모드 활성. 2026-05-22 demo hot-fix —
-              // frame partial 에 @container aspect-ratio 회전이 들어가서 fixed px 제약 사라짐.
-              if ((!isPendingLayout && !isEditMode) || !onZoneResize) return;
+              // resize 는 pendingLayout OR image-zone 편집 모드 활성. 2026-05-22
+              // demo hot-fix — frame partial 에 @container aspect-ratio 회전이
+              // 들어가서 fixed px 제약 사라짐. IMP-90 u12: text/structure 모드
+              // 에서는 zone resize 비활성 (mutually exclusive per editGates).
+              if ((!isPendingLayout && !editGates.zoneGestures) || !onZoneResize) return;
               if (!measuredSlideBody) return;
               ev.preventDefault();
               ev.stopPropagation();
@@ -637,7 +847,10 @@ export default function SlideCanvas({
               ev: React.MouseEvent<HTMLDivElement>
             ) => {
               ev.stopPropagation();
-              const canDrag = !!((isPendingLayout || isEditMode) && measuredSlideBody && onZoneResize);
+              // IMP-90 u12: zone drag is image-zone-mode-only (text /
+              // structure suppress canDrag; non-zoneGestures click still
+              // triggers onZoneClick via the !dragged branch on mouse-up).
+              const canDrag = !!((isPendingLayout || editGates.zoneGestures) && measuredSlideBody && onZoneResize);
               const startMouseX = ev.clientX;
               const startMouseY = ev.clientY;
               const startGeom = { ...localGeom };
@@ -856,12 +1069,14 @@ export default function SlideCanvas({
                   </div>
                 )}
 
-                {/* Step C : zone resize handles — 8 방향. pendingLayout OR 편집 모드 활성.
-                    2026-05-22 demo hot-fix — frame partial 에 @container aspect-ratio 회전
-                    들어간 후 fixed px 제약 사라져 편집 모드 resize 도 의미 있음.
+                {/* Step C : zone resize handles — 8 방향. pendingLayout OR image-zone
+                    편집 모드 활성. 2026-05-22 demo hot-fix — frame partial 에 @container
+                    aspect-ratio 회전 들어간 후 fixed px 제약 사라져 image-zone 모드 resize
+                    도 의미 있음. IMP-90 u12: text / structure 모드에서는 zone resize
+                    affordance 미노출 (editGates.zoneGestures = image-zone only).
                     edge handle (top/bottom/left/right) : 한 boundary 이동
                     corner handle (nw/ne/sw/se) : 두 boundary 동시. */}
-                {(isPendingLayout || isEditMode) && onZoneResize && (
+                {(isPendingLayout || editGates.zoneGestures) && onZoneResize && (
                   <>
                     {/* top edge */}
                     <div
@@ -941,8 +1156,10 @@ export default function SlideCanvas({
                     strips intercept the perimeter while the un-covered iframe
                     interior keeps text-edit reachability intact.
                     pendingLayout mode already has wrapper pointerEvents:auto,
-                    so these surfaces are only needed in edit mode. */}
-                {isEditMode && !isPendingLayout && onZoneResize && (
+                    so these surfaces are only needed in edit mode.
+                    IMP-90 u12: image-zone-mode-only — text / structure 모드는
+                    zone drag 안 함 (editGates.zoneGestures = false 두 모드 모두). */}
+                {editGates.zoneGestures && !isPendingLayout && onZoneResize && (
                   <>
                     <div
                       onMouseDown={handleZoneMouseDown}
@@ -987,6 +1204,39 @@ export default function SlideCanvas({
             );
           })}
 
+          {/* IMP-90 (#90) u14 — structure edit overlay (slot reorder +
+              hide). Renders only in `editMode === "structure"` over each
+              measured zone, positioned at the zone's top-right inside the
+              slide-absolute coord space. Slot keys come from u14 iframe
+              traversal (`slotKeysByZone`). Mutations emit through
+              onStructureEdit; u15 will debounce + PUT. */}
+          {!isPendingLayout && editMode === "structure" && finalHtmlUrl &&
+            slidePlan?.zones.map((zone) => {
+              const m = measuredZones[zone.zone_id];
+              if (!m) return null;
+              const slotKeys = slotKeysByZone[zone.zone_id] ?? [];
+              const current = structureOverrides?.[zone.zone_id];
+              return (
+                <div
+                  key={`struct-${zone.id}`}
+                  className="absolute z-30"
+                  style={{
+                    left: m.x * W_SCALED,
+                    top: m.y * H_SCALED,
+                    width: m.w * W_SCALED,
+                    pointerEvents: "none",
+                  }}
+                >
+                  <StructureEditOverlay
+                    zoneId={zone.zone_id}
+                    slotKeys={slotKeys}
+                    current={current}
+                    onChange={onStructureEdit}
+                  />
+                </div>
+              );
+            })}
+
           {/* ── IMP-51 (#79) u8 — user-content image edit overlay ──
             Activates only in edit mode when an image_id appears in either
             `imageOverrides` (u11-fed persisted axis) or `measuredImages`
@@ -1014,7 +1264,11 @@ export default function SlideCanvas({
             `slideCanvasDragMath.ts` so the boundary contract Codex #16
             verified is exercised directly by vitest (mirror of how IMP-54
             u3 split the zone math out of SlideCanvas). */}
-          {!isPendingLayout && isEditMode && finalHtmlUrl && onImageResize &&
+          {/* IMP-90 u12: image overlay is image-zone-mode-only. text /
+              structure 모드에서는 image drag/resize affordance 미노출
+              (editGates.imageOverlay = false). pendingLayout 도 동일하게
+              suppress (computeEditModeGates 가 모두 false 반환). */}
+          {!isPendingLayout && editGates.imageOverlay && finalHtmlUrl && onImageResize &&
             Object.entries({ ...measuredImages, ...(imageOverrides ?? {}) }).map(
               ([imageId]) => {
                 const persisted = imageOverrides?.[imageId];

Front/client/src/components/StructureEditOverlay.tsx

@@ -0,0 +1,165 @@
+/**
+ * IMP-90 (#90) u14 — Structure edit overlay.
+ *
+ * React component + pure helpers that present a per-zone slot list with
+ * reorder (↑ / ↓) and hide (👁 / 🚫) affordances. Mounted by SlideCanvas
+ * when `editMode === "structure"`. Emits a `StructureOverridePerZone`
+ * tuple `{slot_order, hidden_slots}` through `onChange`; u15 will debounce
+ * + PUT this to `/api/user-overrides` (NOT u14 scope), and u16 reads the
+ * persisted axis at the next CLI generate run.
+ *
+ * SCOPE LOCK (binding contract):
+ *   - inner shape = `{slot_order, hidden_slots}` ONLY.
+ *   - frame swap stays on the existing `frames` axis (u6 backend resolver
+ *     rejects frame-swap-shaped inner keys).
+ *   - per-slot text content NEVER mutated here — `text_overrides` axis
+ *     (u4/u5/u13) handles that exclusively.
+ *
+ * The exported pure helpers (`resolveEffectiveSlotOrder`, `moveItem`) are
+ * the unit's vitest surface; React rendering is NOT tested because the
+ * Front package devDependencies do not include jsdom / @testing-library
+ * (verified by u11/u12/u13 test pattern).
+ */
+import type {
+  StructureOverridePerZone,
+} from "../services/userOverridesApi";
+
+export interface StructureEditOverlayProps {
+  zoneId: string;
+  /** Discovered slot keys for this zone (e.g. from iframe DOM
+   *  `data-text-path` prefixes). Order = backend default. */
+  slotKeys: ReadonlyArray<string>;
+  /** Current persisted override (or undefined). `slot_order` reorders the
+   *  discovered keys; missing keys keep backend order at the tail. */
+  current?: StructureOverridePerZone;
+  /** Emitted on every user mutation. u15 wires this to autosave. */
+  onChange?: (zoneId: string, next: StructureOverridePerZone) => void;
+}
+
+/** Apply `slot_order` override to the discovered slot list. Unknown
+ *  override entries are dropped; missing discovered keys are appended in
+ *  backend order so the user never loses a slot by partial-override. */
+export function resolveEffectiveSlotOrder(
+  slotKeys: ReadonlyArray<string>,
+  slotOrder?: ReadonlyArray<string> | null,
+): string[] {
+  if (!slotOrder || slotOrder.length === 0) return [...slotKeys];
+  const allowed = new Set(slotKeys);
+  const seen = new Set<string>();
+  const ordered: string[] = [];
+  for (const k of slotOrder) {
+    if (typeof k === "string" && allowed.has(k) && !seen.has(k)) {
+      ordered.push(k);
+      seen.add(k);
+    }
+  }
+  for (const k of slotKeys) {
+    if (!seen.has(k)) ordered.push(k);
+  }
+  return ordered;
+}
+
+/** Move `arr[index]` by `delta` positions. Out-of-range returns a fresh
+ *  copy of the input (defensive: caller can always treat the result as a
+ *  new reference). */
+export function moveItem<T>(
+  arr: ReadonlyArray<T>,
+  index: number,
+  delta: number,
+): T[] {
+  const next = arr.slice();
+  const target = index + delta;
+  if (
+    index < 0 ||
+    index >= next.length ||
+    target < 0 ||
+    target >= next.length
+  ) {
+    return next;
+  }
+  const tmp = next[index];
+  next[index] = next[target];
+  next[target] = tmp;
+  return next;
+}
+
+export default function StructureEditOverlay({
+  zoneId,
+  slotKeys,
+  current,
+  onChange,
+}: StructureEditOverlayProps) {
+  const effective = resolveEffectiveSlotOrder(slotKeys, current?.slot_order);
+  const hidden = new Set(current?.hidden_slots ?? []);
+  const emit = (nextOrder: string[], nextHidden: Set<string>) => {
+    onChange?.(zoneId, {
+      slot_order: nextOrder,
+      hidden_slots: Array.from(nextHidden),
+    });
+  };
+  return (
+    <div
+      data-testid={`structure-overlay-${zoneId}`}
+      className="bg-white/95 border border-emerald-300 rounded shadow p-2 flex flex-col gap-1 text-[10px]"
+      style={{ pointerEvents: "auto" }}
+    >
+      <div className="font-bold uppercase tracking-wider text-emerald-700 mb-1">
+        ▦ {zoneId}
+      </div>
+      {effective.length === 0 ? (
+        <div className="text-slate-400 italic">slot 없음</div>
+      ) : (
+        effective.map((key, i) => (
+          <div
+            key={key}
+            data-testid={`slot-${zoneId}-${key}`}
+            className="flex items-center gap-1"
+          >
+            <span
+              className={`flex-1 truncate ${
+                hidden.has(key) ? "text-slate-400 line-through" : "text-slate-700"
+              }`}
+            >
+              {key}
+            </span>
+            <button
+              type="button"
+              data-testid={`slot-up-${zoneId}-${key}`}
+              disabled={i === 0}
+              onClick={() => emit(moveItem(effective, i, -1), hidden)}
+              className="px-1 rounded border border-slate-200 disabled:opacity-30 hover:bg-slate-100"
+              title="위로"
+            >
+              ↑
+            </button>
+            <button
+              type="button"
+              data-testid={`slot-down-${zoneId}-${key}`}
+              disabled={i === effective.length - 1}
+              onClick={() => emit(moveItem(effective, i, 1), hidden)}
+              className="px-1 rounded border border-slate-200 disabled:opacity-30 hover:bg-slate-100"
+              title="아래로"
+            >
+              ↓
+            </button>
+            <button
+              type="button"
+              data-testid={`slot-hide-${zoneId}-${key}`}
+              aria-pressed={hidden.has(key)}
+              onClick={() => {
+                const nh = new Set(hidden);
+                if (nh.has(key)) nh.delete(key);
+                else nh.add(key);
+                emit(effective, nh);
+              }}
+              className="px-1 rounded border border-slate-200 hover:bg-slate-100"
+              title={hidden.has(key) ? "표시" : "숨김"}
+            >
+              {hidden.has(key) ? "🚫" : "👁"}
+            </button>
+          </div>
+        ))
+      )}
+    </div>
+  );
+}

Front/client/src/services/userOverridesApi.ts

@@ -75,6 +75,37 @@ export type ImageOverridesOverride = Record<string, ImageOverride>;
  */
 export type ManualSectionAssignmentOverride = boolean;
 
+/**
+ * IMP-56 #90 u10 — Step-22 text-edit persist axis. Keyed by `zone_id`; the
+ * inner mapping is `text_path` (= `{slot_key}.{line_index}`) → line value.
+ * The `text_path` stamp is emitted by `src/text_path_stamper.py` (u8) and
+ * applied at Step 13 (u9); the value is consumed by `text_override_resolver`
+ * (u4) and applied at Step 12 (u5). Stale paths (frame swap / layout
+ * regression between sessions) are tolerated by the backend resolver as
+ * `skipped`, NOT raised — so the on-disk axis is forward-compat with layout
+ * and frame churn. Mirrors Python `KNOWN_AXES` entry (u1) and Vite
+ * `KNOWN_USER_OVERRIDES_AXES` allowlist entry (u3).
+ */
+export type TextOverridesPerZone = Record<string, string>;
+export type TextOverridesOverride = Record<string, TextOverridesPerZone>;
+
+/**
+ * IMP-56 #90 u10 — Step-22 structure-edit persist axis. Keyed by `zone_id`;
+ * the inner mapping is SCOPE-LOCKED to `{slot_order, hidden_slots}` — slot
+ * reorder + slot hide only. Frame swap stays on the existing `frames` axis;
+ * the `structure_override_resolver` (u6) rejects frame-swap-shaped inner
+ * keys at the validate gate so Phase Z's no-AI-HTML-structure invariant
+ * holds across this persisted axis too. Per-slot `list[str]` line content
+ * is NEVER mutated by the u7 Step-12 apply — that is the `text_overrides`
+ * axis above. Mirrors Python `KNOWN_AXES` entry (u2) and Vite
+ * `KNOWN_USER_OVERRIDES_AXES` allowlist entry (u3).
+ */
+export type StructureOverridePerZone = {
+  slot_order?: string[];
+  hidden_slots?: string[];
+};
+export type StructureOverridesOverride = Record<string, StructureOverridePerZone>;
+
 /** Full on-disk schema. All axes optional — file may carry any subset. */
 export interface UserOverrides {
   layout: string;
@@ -83,6 +114,8 @@ export interface UserOverrides {
   zone_sections: ZoneSectionsOverride;
   image_overrides: ImageOverridesOverride;
   manual_section_assignment: ManualSectionAssignmentOverride;
+  text_overrides: TextOverridesOverride;
+  structure_overrides: StructureOverridesOverride;
 }
 
 /** Partial-mutation payload. `null` is the explicit clear sentinel (mirrors u4). */

Front/client/src/types/designAgent.ts

@@ -227,6 +227,15 @@ export interface UserSelection {
     // (Front/vite.config.ts), and `ManualSectionAssignmentOverride`
     // (services/userOverridesApi.ts).
     manual_section_assignment: boolean;
+    // IMP-56 #90 u10/u15 — Step-22 text + structure persist axes. Mirrors
+    // services/userOverridesApi.ts (`TextOverridesOverride` /
+    // `StructureOverridesOverride`). `text_overrides[zoneId][textPath] = value`
+    // is fed by SlideCanvas u13 focusout capture + Home u15 autosave;
+    // `structure_overrides[zoneId] = {slot_order, hidden_slots}` is fed by
+    // u14 overlay + u15 autosave. Both seeded `{}` in createInitialUserSelection
+    // and restored on reopen via applyPersistedNonFrameOverrides.
+    text_overrides: Record<string, Record<string, string>>;
+    structure_overrides: Record<string, { slot_order?: string[]; hidden_slots?: string[] }>;
   };
 }
 

Front/client/src/utils/slidePlanUtils.ts

@@ -1,5 +1,11 @@
 import type { UserSelection, SlidePlan, Zone, InternalRegion, LayoutPresetId } from "../types/designAgent";
-import type { UserOverrides } from "../services/userOverridesApi";
+import type {
+  StructureOverridePerZone,
+  StructureOverridesOverride,
+  TextOverridesOverride,
+  TextOverridesPerZone,
+  UserOverrides,
+} from "../services/userOverridesApi";
 import { computeZonePositions } from "../services/designAgentApi";
 
 // ─── IMP-52 u6 — restore-on-reopen helpers (pure, exported for testing) ────
@@ -99,9 +105,74 @@ export function applyPersistedNonFrameOverrides(
   if (typeof persisted.manual_section_assignment === "boolean") {
     next.manual_section_assignment = persisted.manual_section_assignment;
   }
+  // IMP-56 (#90) u15 — layer the two Step-22 persist axes through the
+  // u10 extract helpers; their `_isPlainObject` + dedupe gates already
+  // sanitize foreign / hand-edited payloads, so reopen never poisons
+  // memory with non-string values or non-list slot_order entries.
+  next.text_overrides = extractPersistedTextOverrides(persisted);
+  next.structure_overrides = extractPersistedStructureOverrides(persisted);
   return { ...selection, overrides: next };
 }
 
+// ─── IMP-56 #90 u10 — typed extract helpers for the two new persist axes ───
+// Pure helpers that defensively sanitize Step-22 text_overrides and
+// structure_overrides payloads off a `Partial<UserOverrides>` (typed by u10's
+// userOverridesApi extension). They mirror the backend validation gates
+// (`text_override_resolver` u4 / `structure_override_resolver` u6) on the
+// frontend so a hand-edited or schema-drift payload cannot poison memory.
+// Layering onto `UserSelection.overrides` arrives in u14~u16; until then
+// capture / autosave / restore wiring units consume these as typed.
+
+function _isPlainObject(x: unknown): x is Record<string, unknown> {
+  return !!x && typeof x === "object" && !Array.isArray(x);
+}
+
+function _dedupeStringList(arr: unknown): string[] {
+  if (!Array.isArray(arr)) return [];
+  const seen = new Set<string>();
+  const out: string[] = [];
+  for (const k of arr) {
+    if (typeof k === "string" && k.length > 0 && !seen.has(k)) {
+      seen.add(k);
+      out.push(k);
+    }
+  }
+  return out;
+}
+
+export function extractPersistedTextOverrides(
+  persisted: Partial<UserOverrides> | null | undefined,
+): TextOverridesOverride {
+  const raw = persisted?.text_overrides;
+  if (!_isPlainObject(raw)) return {};
+  const out: TextOverridesOverride = {};
+  for (const [zoneId, perZone] of Object.entries(raw)) {
+    if (!zoneId || !_isPlainObject(perZone)) continue;
+    const safe: TextOverridesPerZone = {};
+    for (const [textPath, value] of Object.entries(perZone)) {
+      if (textPath && typeof value === "string") safe[textPath] = value;
+    }
+    out[zoneId] = safe;
+  }
+  return out;
+}
+
+export function extractPersistedStructureOverrides(
+  persisted: Partial<UserOverrides> | null | undefined,
+): StructureOverridesOverride {
+  const raw = persisted?.structure_overrides;
+  if (!_isPlainObject(raw)) return {};
+  const out: StructureOverridesOverride = {};
+  for (const [zoneId, perZone] of Object.entries(raw)) {
+    if (!zoneId || !_isPlainObject(perZone)) continue;
+    const safe: StructureOverridePerZone = {};
+    if (Array.isArray(perZone.slot_order)) safe.slot_order = _dedupeStringList(perZone.slot_order);
+    if (Array.isArray(perZone.hidden_slots)) safe.hidden_slots = _dedupeStringList(perZone.hidden_slots);
+    out[zoneId] = safe;
+  }
+  return out;
+}
+
 /**
  * Remap persisted frames (`unit_id` → template_id) to the in-memory
  * `zone_frames` (region.id → template_id) using the freshly built
@@ -174,6 +245,12 @@ export function createInitialUserSelection(slidePlan?: SlidePlan | null): UserSe
       // here via `saveImageOverride` (SlideCanvas drag/resize handler) and
       // are seeded on reopen via `applyPersistedNonFrameOverrides`.
       image_overrides: {},
+      // IMP-56 (#90) u15 — Step-22 axes seeded empty. Entries land here
+      // via `saveTextOverride` (u13 focusout capture) and
+      // `saveStructureOverride` (u14 overlay) and are restored on reopen
+      // via `applyPersistedNonFrameOverrides`.
+      text_overrides: {},
+      structure_overrides: {},
       // IMP-55 (#93) u3 — bool intent marker seeded `false` so a fresh
       // MDX open (no persisted file, or persisted file with axis absent)
       // never forwards `overrides.zoneSections` to the backend. The marker
@@ -229,6 +306,60 @@ export function saveImageOverride(
   };
 }
 
+/**
+ * IMP-56 (#90) u15 — record a single text-line capture (zone_id, text_path,
+ * value) onto the in-memory selection's `text_overrides` axis. Mirrors
+ * `saveImageOverride` (pure / immutable). u13's focusout capture emits one
+ * entry per finished edit; Home u15's handler funnels each emit through this
+ * helper before scheduling the debounced PUT (`saveUserOverrides` 300ms).
+ */
+export function saveTextOverride(
+  selection: UserSelection,
+  zoneId: string,
+  textPath: string,
+  value: string,
+): UserSelection {
+  const prevZone = selection.overrides.text_overrides[zoneId] ?? {};
+  return {
+    ...selection,
+    overrides: {
+      ...selection.overrides,
+      text_overrides: {
+        ...selection.overrides.text_overrides,
+        [zoneId]: { ...prevZone, [textPath]: value },
+      },
+    },
+  };
+}
+
+/**
+ * IMP-56 (#90) u15 — record a single structure capture (zone_id ↦
+ * {slot_order, hidden_slots}) onto the in-memory selection's
+ * `structure_overrides` axis. Scope-locked to slot reorder + hide (frame
+ * swap stays on the `frames` axis). u14's overlay emits one entry per
+ * user mutation; Home u15's handler funnels each emit through this
+ * helper before scheduling the debounced PUT.
+ */
+export function saveStructureOverride(
+  selection: UserSelection,
+  zoneId: string,
+  perZone: StructureOverridePerZone,
+): UserSelection {
+  return {
+    ...selection,
+    overrides: {
+      ...selection.overrides,
+      structure_overrides: {
+        ...selection.overrides.structure_overrides,
+        [zoneId]: {
+          ...(perZone.slot_order !== undefined && { slot_order: [...perZone.slot_order] }),
+          ...(perZone.hidden_slots !== undefined && { hidden_slots: [...perZone.hidden_slots] }),
+        },
+      },
+    },
+  };
+}
+
 export function saveZoneSizes(selection: UserSelection, groupId: string, sizes: number[]): UserSelection {
   return {
     ...selection,

Front/client/tests/imp90_connect_endpoint.test.ts

@@ -0,0 +1,282 @@
+// IMP-56 (#90) u18 — vitest coverage for the vite POST /api/connect
+// middleware and its supporting mirrorDirRecursive helper.
+//
+// Scope:
+//   1) mirrorDirRecursive (pure helper):
+//      - absent src → returns 0 (no-throw, no dst creation).
+//      - file-only src → flat copy + count.
+//      - nested src → recursive copy + count.
+//      - overwrites pre-existing dst files (cel mirror semantics).
+//   2) handleConnectMirror (POST):
+//      - method != POST → false (chain continues; next middleware may handle).
+//      - invalid JSON / non-object body → 400.
+//      - missing run_id or slug → 400.
+//      - invalid run_id or slug (key gate / path traversal) → 400.
+//      - final.html missing → 404.
+//      - success without run-assets dir → 200, assets_copied: 0, html copy ok.
+//      - success with run-assets dir → 200, assets_copied = file count, dst dir
+//        populated.
+//      - dstSlidesDir auto-created when celRoot/public/slides missing.
+//
+// Tests exercise the pure handler with mock req/res — no real vite server.
+
+import { describe, it, expect, beforeEach, afterEach } from "vitest";
+import { EventEmitter } from "node:events";
+import * as fs from "node:fs";
+import * as os from "node:os";
+import * as path from "node:path";
+import {
+  handleConnectMirror,
+  mirrorDirRecursive,
+} from "../../vite.config";
+
+function makeMockRes() {
+  const state = {
+    statusCode: 0,
+    headers: {} as Record<string, string>,
+    body: "",
+    ended: false,
+  };
+  return {
+    state,
+    res: {
+      writeHead(status: number, headers?: Record<string, string>) {
+        state.statusCode = status;
+        if (headers) state.headers = headers;
+      },
+      end(body?: string) {
+        state.body = body ?? "";
+        state.ended = true;
+      },
+    },
+  };
+}
+
+function makeMockReq(opts: {
+  method?: string;
+}): EventEmitter & { method?: string; send: (body: string) => void } {
+  const ee = new EventEmitter() as EventEmitter & {
+    method?: string;
+    send: (body: string) => void;
+  };
+  ee.method = opts.method;
+  ee.send = (body: string) => {
+    if (body.length > 0) ee.emit("data", Buffer.from(body, "utf-8"));
+    ee.emit("end");
+  };
+  return ee;
+}
+
+function seedRun(daRoot: string, runId: string, htmlBody: string): string {
+  const runDir = path.join(daRoot, "data", "runs", runId, "phase_z2");
+  fs.mkdirSync(runDir, { recursive: true });
+  const html = path.join(runDir, "final.html");
+  fs.writeFileSync(html, htmlBody, "utf-8");
+  return runDir;
+}
+
+describe("mirrorDirRecursive (IMP-56 #90 u18)", () => {
+  let tmp: string;
+
+  beforeEach(() => {
+    tmp = fs.mkdtempSync(path.join(os.tmpdir(), "imp90-u18-mirror-"));
+  });
+
+  afterEach(() => {
+    fs.rmSync(tmp, { recursive: true, force: true });
+  });
+
+  it("returns 0 and does not throw when src absent", () => {
+    const dst = path.join(tmp, "dst");
+    const n = mirrorDirRecursive(path.join(tmp, "missing"), dst);
+    expect(n).toBe(0);
+    expect(fs.existsSync(dst)).toBe(false);
+  });
+
+  it("returns 0 when src exists but is a file (not a directory)", () => {
+    const srcFile = path.join(tmp, "src.txt");
+    fs.writeFileSync(srcFile, "x", "utf-8");
+    const dst = path.join(tmp, "dst");
+    const n = mirrorDirRecursive(srcFile, dst);
+    expect(n).toBe(0);
+    expect(fs.existsSync(dst)).toBe(false);
+  });
+
+  it("flat-copies file entries and returns the file count", () => {
+    const src = path.join(tmp, "src");
+    fs.mkdirSync(src);
+    fs.writeFileSync(path.join(src, "a.css"), "/*a*/", "utf-8");
+    fs.writeFileSync(path.join(src, "b.png"), "PNG", "utf-8");
+    const dst = path.join(tmp, "dst");
+    const n = mirrorDirRecursive(src, dst);
+    expect(n).toBe(2);
+    expect(fs.readFileSync(path.join(dst, "a.css"), "utf-8")).toBe("/*a*/");
+    expect(fs.readFileSync(path.join(dst, "b.png"), "utf-8")).toBe("PNG");
+  });
+
+  it("recurses into nested directories and counts only files", () => {
+    const src = path.join(tmp, "src");
+    fs.mkdirSync(path.join(src, "nested", "deep"), { recursive: true });
+    fs.writeFileSync(path.join(src, "root.txt"), "r", "utf-8");
+    fs.writeFileSync(path.join(src, "nested", "n.txt"), "n", "utf-8");
+    fs.writeFileSync(path.join(src, "nested", "deep", "d.txt"), "d", "utf-8");
+    const dst = path.join(tmp, "dst");
+    const n = mirrorDirRecursive(src, dst);
+    expect(n).toBe(3);
+    expect(fs.readFileSync(path.join(dst, "nested", "deep", "d.txt"), "utf-8"))
+      .toBe("d");
+  });
+
+  it("overwrites pre-existing files in dst (cel mirror semantics)", () => {
+    const src = path.join(tmp, "src");
+    fs.mkdirSync(src);
+    fs.writeFileSync(path.join(src, "a.css"), "NEW", "utf-8");
+    const dst = path.join(tmp, "dst");
+    fs.mkdirSync(dst);
+    fs.writeFileSync(path.join(dst, "a.css"), "OLD", "utf-8");
+    mirrorDirRecursive(src, dst);
+    expect(fs.readFileSync(path.join(dst, "a.css"), "utf-8")).toBe("NEW");
+  });
+});
+
+describe("handleConnectMirror (IMP-56 #90 u18)", () => {
+  let daRoot: string;
+  let celRoot: string;
+
+  beforeEach(() => {
+    daRoot = fs.mkdtempSync(path.join(os.tmpdir(), "imp90-u18-da-"));
+    celRoot = fs.mkdtempSync(path.join(os.tmpdir(), "imp90-u18-cel-"));
+  });
+
+  afterEach(() => {
+    fs.rmSync(daRoot, { recursive: true, force: true });
+    fs.rmSync(celRoot, { recursive: true, force: true });
+  });
+
+  it("returns false (next chained) when method != POST", () => {
+    const req = makeMockReq({ method: "GET" });
+    const { res, state } = makeMockRes();
+    const handled = handleConnectMirror(req, res, daRoot, celRoot);
+    expect(handled).toBe(false);
+    expect(state.ended).toBe(false);
+  });
+
+  it("returns 400 on invalid JSON body", () => {
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    const handled = handleConnectMirror(req, res, daRoot, celRoot);
+    expect(handled).toBe(true);
+    req.send("{not-json}");
+    expect(state.statusCode).toBe(400);
+    expect(JSON.parse(state.body).error).toBe("invalid JSON");
+  });
+
+  it("returns 400 when body is not a JSON object (array root)", () => {
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    handleConnectMirror(req, res, daRoot, celRoot);
+    req.send(JSON.stringify(["not", "an", "object"]));
+    expect(state.statusCode).toBe(400);
+    expect(JSON.parse(state.body).error).toBe("body must be a JSON object");
+  });
+
+  it("returns 400 when run_id or slug is missing", () => {
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    handleConnectMirror(req, res, daRoot, celRoot);
+    req.send(JSON.stringify({ run_id: "abc" })); // slug missing
+    expect(state.statusCode).toBe(400);
+    expect(JSON.parse(state.body).error).toBe("missing run_id or slug");
+  });
+
+  it("returns 400 when run_id contains path traversal", () => {
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    handleConnectMirror(req, res, daRoot, celRoot);
+    req.send(JSON.stringify({ run_id: "../escape", slug: "03" }));
+    expect(state.statusCode).toBe(400);
+    expect(JSON.parse(state.body).error).toBe("invalid run_id or slug");
+  });
+
+  it("returns 400 when slug contains a forward slash", () => {
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    handleConnectMirror(req, res, daRoot, celRoot);
+    req.send(JSON.stringify({ run_id: "valid_id", slug: "03/etc" }));
+    expect(state.statusCode).toBe(400);
+    expect(JSON.parse(state.body).error).toBe("invalid run_id or slug");
+  });
+
+  it("returns 404 when final.html does not exist for run_id", () => {
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    handleConnectMirror(req, res, daRoot, celRoot);
+    req.send(JSON.stringify({ run_id: "ghost_run", slug: "03" }));
+    expect(state.statusCode).toBe(404);
+    expect(JSON.parse(state.body).error).toBe("final.html not found");
+  });
+
+  it("copies final.html to cel/public/slides/<slug>.html on success", () => {
+    seedRun(daRoot, "mdx03_run", "<html>03</html>");
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    handleConnectMirror(req, res, daRoot, celRoot);
+    req.send(JSON.stringify({ run_id: "mdx03_run", slug: "03" }));
+
+    expect(state.statusCode).toBe(200);
+    const dstHtml = path.join(celRoot, "public", "slides", "03.html");
+    expect(fs.existsSync(dstHtml)).toBe(true);
+    expect(fs.readFileSync(dstHtml, "utf-8")).toBe("<html>03</html>");
+    const body = JSON.parse(state.body);
+    expect(body.success).toBe(true);
+    expect(body.run_id).toBe("mdx03_run");
+    expect(body.slug).toBe("03");
+    expect(body.assets_copied).toBe(0);
+    expect(body.html_target).toBe(dstHtml);
+  });
+
+  it("auto-creates cel/public/slides when missing", () => {
+    seedRun(daRoot, "mdx04_run", "<html>04</html>");
+    expect(fs.existsSync(path.join(celRoot, "public", "slides"))).toBe(false);
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    handleConnectMirror(req, res, daRoot, celRoot);
+    req.send(JSON.stringify({ run_id: "mdx04_run", slug: "04" }));
+    expect(state.statusCode).toBe(200);
+    expect(fs.existsSync(path.join(celRoot, "public", "slides", "04.html"))).toBe(true);
+  });
+
+  it("mirrors assets/ recursively when present in the run dir", () => {
+    const runDir = seedRun(daRoot, "mdx05_run", "<html>05</html>");
+    fs.mkdirSync(path.join(runDir, "assets", "css"), { recursive: true });
+    fs.writeFileSync(path.join(runDir, "assets", "main.css"), "*{}", "utf-8");
+    fs.writeFileSync(path.join(runDir, "assets", "css", "extra.css"), "p{}", "utf-8");
+
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    handleConnectMirror(req, res, daRoot, celRoot);
+    req.send(JSON.stringify({ run_id: "mdx05_run", slug: "05" }));
+
+    expect(state.statusCode).toBe(200);
+    expect(JSON.parse(state.body).assets_copied).toBe(2);
+    expect(fs.readFileSync(path.join(celRoot, "public", "slides", "assets", "main.css"), "utf-8"))
+      .toBe("*{}");
+    expect(fs.readFileSync(path.join(celRoot, "public", "slides", "assets", "css", "extra.css"), "utf-8"))
+      .toBe("p{}");
+  });
+
+  it("overwrites pre-existing cel slide html (re-Connect semantics)", () => {
+    seedRun(daRoot, "mdx03_run", "NEW");
+    const dstSlidesDir = path.join(celRoot, "public", "slides");
+    fs.mkdirSync(dstSlidesDir, { recursive: true });
+    fs.writeFileSync(path.join(dstSlidesDir, "03.html"), "OLD", "utf-8");
+
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    handleConnectMirror(req, res, daRoot, celRoot);
+    req.send(JSON.stringify({ run_id: "mdx03_run", slug: "03" }));
+
+    expect(state.statusCode).toBe(200);
+    expect(fs.readFileSync(path.join(dstSlidesDir, "03.html"), "utf-8")).toBe("NEW");
+  });
+});

Front/client/tests/imp90_edit_mode_gating.test.tsx

@@ -0,0 +1,219 @@
+// IMP-90 (#90) u12 — vitest coverage for `computeEditModeGates`, the pure
+// helper that drives SlideCanvas's mutually-exclusive gesture gating.
+// u11 introduced the `EditMode` enum + toolbar; u12 splits the prior
+// `isEditMode` shim (which fired ALL gates whenever any edit mode was
+// active) into 5 per-gate booleans:
+//   textEditing       — designMode + contentEditable (text mode only).
+//   imageSelection    — in-iframe user-content image click listener
+//                       (image-zone mode only).
+//   iframePointerAuto — iframe pointer-events:auto so in-iframe gestures
+//                       (text caret OR image click) can reach the doc.
+//                       text mode + image-zone mode; structure stays
+//                       pe:none because u14 will overlay React controls.
+//   zoneGestures      — zone resize 8-handle ring + drag perimeter strips
+//                       + canDrag in handleZoneMouseDown
+//                       (image-zone mode only).
+//   imageOverlay      — React-side image edit overlay (image-zone only).
+//
+// Mutually-exclusive contract (from the issue body's "discriminated edit
+// mode"): no editMode value enables both `textEditing` and either
+// `imageSelection` or `zoneGestures` simultaneously. structure mode is
+// the no-op placeholder — u14 will plant the structure overlay there.
+// pendingLayout fully suppresses every gate (mirrors the existing
+// useEffect that forces editMode='off' on pendingLayout entry).
+//
+// Scope guard: this test exercises the pure helper only — no React
+// rendering, no DOM. testing-library/react is NOT in devDependencies
+// (verified in Front/package.json); helper-level coverage is the
+// established u11 pattern.
+
+import { describe, it, expect } from "vitest";
+import {
+  computeEditModeGates,
+  type EditMode,
+  type EditModeGates,
+} from "../src/components/SlideCanvas";
+
+const ALL_MODES: EditMode[] = ["off", "text", "structure", "image-zone"];
+
+describe("computeEditModeGates (IMP-90 u12) — pendingLayout suppression", () => {
+  it.each<EditMode>(ALL_MODES)(
+    "pendingLayout=true forces every gate false (editMode=%s)",
+    (mode) => {
+      const g = computeEditModeGates(mode, true);
+      expect(g).toEqual<EditModeGates>({
+        textEditing: false,
+        imageSelection: false,
+        iframePointerAuto: false,
+        zoneGestures: false,
+        imageOverlay: false,
+      });
+    }
+  );
+});
+
+describe("computeEditModeGates (IMP-90 u12) — off baseline", () => {
+  it("editMode=off pendingLayout=false: every gate false", () => {
+    expect(computeEditModeGates("off", false)).toEqual<EditModeGates>({
+      textEditing: false,
+      imageSelection: false,
+      iframePointerAuto: false,
+      zoneGestures: false,
+      imageOverlay: false,
+    });
+  });
+});
+
+describe("computeEditModeGates (IMP-90 u12) — text mode", () => {
+  const g = computeEditModeGates("text", false);
+
+  it("textEditing = true (designMode + contentEditable activate)", () => {
+    expect(g.textEditing).toBe(true);
+  });
+  it("iframePointerAuto = true (caret needs to reach the doc)", () => {
+    expect(g.iframePointerAuto).toBe(true);
+  });
+  it("imageSelection = false (no in-iframe image click listener)", () => {
+    expect(g.imageSelection).toBe(false);
+  });
+  it("zoneGestures = false (no zone resize / drag affordances)", () => {
+    expect(g.zoneGestures).toBe(false);
+  });
+  it("imageOverlay = false (no React-side image overlay)", () => {
+    expect(g.imageOverlay).toBe(false);
+  });
+});
+
+describe("computeEditModeGates (IMP-90 u12) — structure mode", () => {
+  const g = computeEditModeGates("structure", false);
+
+  // structure mode is the u14 placeholder — no gestures here yet. All five
+  // gates stay false so the iframe and React overlays remain quiescent
+  // until u14 plants the structure overlay on the React layer.
+  it("every gate false (u14 will plant the structure overlay later)", () => {
+    expect(g).toEqual<EditModeGates>({
+      textEditing: false,
+      imageSelection: false,
+      iframePointerAuto: false,
+      zoneGestures: false,
+      imageOverlay: false,
+    });
+  });
+});
+
+describe("computeEditModeGates (IMP-90 u12) — image-zone mode", () => {
+  const g = computeEditModeGates("image-zone", false);
+
+  it("textEditing = false (contentEditable would steal image clicks)", () => {
+    expect(g.textEditing).toBe(false);
+  });
+  it("imageSelection = true (in-iframe img click → selectedImageId)", () => {
+    expect(g.imageSelection).toBe(true);
+  });
+  it("iframePointerAuto = true (so image clicks reach the doc)", () => {
+    expect(g.iframePointerAuto).toBe(true);
+  });
+  it("zoneGestures = true (zone resize + drag affordances visible)", () => {
+    expect(g.zoneGestures).toBe(true);
+  });
+  it("imageOverlay = true (React-side overlay renders the drag handles)", () => {
+    expect(g.imageOverlay).toBe(true);
+  });
+});
+
+describe("computeEditModeGates (IMP-90 u12) — mutually exclusive contract", () => {
+  it("text mode never co-activates image-zone gates (imageSelection / zoneGestures / imageOverlay)", () => {
+    const g = computeEditModeGates("text", false);
+    expect(g.textEditing).toBe(true);
+    expect(g.imageSelection).toBe(false);
+    expect(g.zoneGestures).toBe(false);
+    expect(g.imageOverlay).toBe(false);
+  });
+
+  it("image-zone mode never co-activates text gates (textEditing)", () => {
+    const g = computeEditModeGates("image-zone", false);
+    expect(g.imageSelection).toBe(true);
+    expect(g.textEditing).toBe(false);
+  });
+
+  it.each<EditMode>(ALL_MODES)(
+    "for every editMode (%s), textEditing AND zoneGestures are NEVER both true",
+    (mode) => {
+      const g = computeEditModeGates(mode, false);
+      expect(g.textEditing && g.zoneGestures).toBe(false);
+    }
+  );
+
+  it.each<EditMode>(ALL_MODES)(
+    "for every editMode (%s), textEditing AND imageOverlay are NEVER both true",
+    (mode) => {
+      const g = computeEditModeGates(mode, false);
+      expect(g.textEditing && g.imageOverlay).toBe(false);
+    }
+  );
+
+  it.each<EditMode>(ALL_MODES)(
+    "for every editMode (%s), textEditing AND imageSelection are NEVER both true",
+    (mode) => {
+      const g = computeEditModeGates(mode, false);
+      expect(g.textEditing && g.imageSelection).toBe(false);
+    }
+  );
+});
+
+describe("computeEditModeGates (IMP-90 u12) — iframePointerAuto coupling", () => {
+  // pe:auto is the iframe-side prerequisite for ANY in-iframe gesture
+  // (text caret OR image click). The helper must NOT advertise an
+  // in-iframe gate as active while pe is none, or those gestures would
+  // be silently swallowed by the wrapper.
+  it.each<EditMode>(ALL_MODES)(
+    "textEditing → iframePointerAuto (editMode=%s)",
+    (mode) => {
+      const g = computeEditModeGates(mode, false);
+      if (g.textEditing) expect(g.iframePointerAuto).toBe(true);
+    }
+  );
+  it.each<EditMode>(ALL_MODES)(
+    "imageSelection → iframePointerAuto (editMode=%s)",
+    (mode) => {
+      const g = computeEditModeGates(mode, false);
+      if (g.imageSelection) expect(g.iframePointerAuto).toBe(true);
+    }
+  );
+});
+
+describe("computeEditModeGates (IMP-90 u12) — referential transparency", () => {
+  it("multiple calls with the same inputs return equal output", () => {
+    const a = computeEditModeGates("image-zone", false);
+    const b = computeEditModeGates("image-zone", false);
+    const c = computeEditModeGates("image-zone", false);
+    expect(a).toEqual(b);
+    expect(b).toEqual(c);
+  });
+
+  it("does not mutate captured state across calls (independent invocations)", () => {
+    const a = computeEditModeGates("text", false);
+    const _b = computeEditModeGates("image-zone", false);
+    // a must still reflect text mode after b's call.
+    expect(a.textEditing).toBe(true);
+    expect(a.imageSelection).toBe(false);
+  });
+});
+
+describe("computeEditModeGates (IMP-90 u12) — gate truthtable snapshot", () => {
+  // Snapshot for human-readable inspection — the per-mode flag layout
+  // is the contract u13 (text capture) and u14 (structure overlay)
+  // will build against. Any change requires updating both this test
+  // AND the consuming gates in SlideCanvas.tsx.
+  it("non-pendingLayout truthtable matches the u12 contract", () => {
+    const rows = (["off", "text", "structure", "image-zone"] as EditMode[]).map(
+      (m) => ({ mode: m, ...computeEditModeGates(m, false) })
+    );
+    expect(rows).toEqual([
+      { mode: "off", textEditing: false, imageSelection: false, iframePointerAuto: false, zoneGestures: false, imageOverlay: false },
+      { mode: "text", textEditing: true, imageSelection: false, iframePointerAuto: true, zoneGestures: false, imageOverlay: false },
+      { mode: "structure", textEditing: false, imageSelection: false, iframePointerAuto: false, zoneGestures: false, imageOverlay: false },
+      { mode: "image-zone", textEditing: false, imageSelection: true, iframePointerAuto: true, zoneGestures: true, imageOverlay: true },
+    ]);
+  });
+});

Front/client/tests/imp90_edit_mode_state.test.tsx

@@ -0,0 +1,133 @@
+// IMP-90 (#90) u11 — vitest coverage for the discriminated EditMode enum
+// and its pure transition helper `nextEditMode`. Replaces the prior single
+// `isEditMode` boolean state. u11 introduces ONLY the state surface + the
+// toolbar UI; gesture gating per mode is u12 (mutually exclusive) and must
+// not regress this contract.
+//
+// Scope (Stage 2 unit u11 contract):
+//   1) EDIT_MODES is the canonical ['text','structure','image-zone'] list
+//      in toolbar render order. 'off' is intentionally excluded from the
+//      iterable because it is the implicit baseline (no button); the
+//      toolbar only renders the three active modes per the u11 design.
+//   2) nextEditMode is a pure (current, requested) -> EditMode mapping
+//      with three rules:
+//        - requested === 'off'              -> 'off'   (explicit exit)
+//        - requested === current            -> 'off'   (toggle exit)
+//        - requested !== current && != 'off'-> requested (mode switch)
+//   3) The helper is referentially transparent — no side effects, no
+//      React, no useState, no DOM. SlideCanvas wires it as the useState
+//      updater callback (`setEditMode((prev) => nextEditMode(prev, m))`),
+//      so covering the helper here covers every toolbar click outcome
+//      directly without DOM rendering. (@testing-library/react is NOT in
+//      devDependencies; this mirrors the imp47b_human_review_toast pattern.)
+//   4) The exported EditMode type union must contain exactly the four
+//      members 'off' | 'text' | 'structure' | 'image-zone'. The runtime
+//      EDIT_MODES list intentionally excludes 'off' (see (1) above).
+//
+// Forward-compat note: u12 will discriminate per-mode gating but MUST NOT
+// alter the (current, requested) -> next contract verified here. Any
+// change to the toggle/switch/exit semantics is a scope-violation against
+// the u11 binding contract.
+
+import { describe, it, expect } from "vitest";
+import {
+  EDIT_MODES,
+  nextEditMode,
+  type EditMode,
+} from "../src/components/SlideCanvas";
+
+describe("EDIT_MODES (IMP-90 u11 — toolbar render order)", () => {
+  it("contains exactly the three active modes in toolbar order", () => {
+    expect(EDIT_MODES).toEqual(["text", "structure", "image-zone"]);
+  });
+
+  it("excludes 'off' — baseline is implicit, no toolbar button", () => {
+    expect(EDIT_MODES).not.toContain("off" as EditMode);
+  });
+
+  it("has length 3", () => {
+    expect(EDIT_MODES.length).toBe(3);
+  });
+});
+
+describe("nextEditMode (IMP-90 u11 — pure transition helper)", () => {
+  describe("explicit 'off' request always exits", () => {
+    it.each<EditMode>(["off", "text", "structure", "image-zone"])(
+      "current=%s, requested=off -> off",
+      (current) => {
+        expect(nextEditMode(current, "off")).toBe("off");
+      }
+    );
+  });
+
+  describe("clicking the active mode toggles back to 'off'", () => {
+    it.each<EditMode>(["text", "structure", "image-zone"])(
+      "current=%s, requested=%s -> off",
+      (mode) => {
+        expect(nextEditMode(mode, mode)).toBe("off");
+      }
+    );
+  });
+
+  describe("clicking a different mode switches", () => {
+    const cases: Array<[EditMode, EditMode]> = [
+      ["off", "text"],
+      ["off", "structure"],
+      ["off", "image-zone"],
+      ["text", "structure"],
+      ["text", "image-zone"],
+      ["structure", "text"],
+      ["structure", "image-zone"],
+      ["image-zone", "text"],
+      ["image-zone", "structure"],
+    ];
+    it.each(cases)("current=%s, requested=%s -> requested", (current, requested) => {
+      expect(nextEditMode(current, requested)).toBe(requested);
+    });
+  });
+
+  it("is referentially transparent — multiple calls with same inputs return same output", () => {
+    const a = nextEditMode("text", "structure");
+    const b = nextEditMode("text", "structure");
+    const c = nextEditMode("text", "structure");
+    expect(a).toBe("structure");
+    expect(b).toBe("structure");
+    expect(c).toBe("structure");
+  });
+
+  it("never returns a value outside the EditMode union", () => {
+    const all: EditMode[] = ["off", "text", "structure", "image-zone"];
+    for (const current of all) {
+      for (const requested of all) {
+        const result = nextEditMode(current, requested);
+        expect(all).toContain(result);
+      }
+    }
+  });
+
+  it("preserves toggle semantics under repeated identical clicks", () => {
+    // off -> text -> off -> text -> off (toggle behavior)
+    let m: EditMode = "off";
+    m = nextEditMode(m, "text");
+    expect(m).toBe("text");
+    m = nextEditMode(m, "text");
+    expect(m).toBe("off");
+    m = nextEditMode(m, "text");
+    expect(m).toBe("text");
+    m = nextEditMode(m, "text");
+    expect(m).toBe("off");
+  });
+
+  it("preserves switch semantics across distinct mode clicks", () => {
+    // off -> text -> structure -> image-zone -> off (via toggle)
+    let m: EditMode = "off";
+    m = nextEditMode(m, "text");
+    expect(m).toBe("text");
+    m = nextEditMode(m, "structure");
+    expect(m).toBe("structure");
+    m = nextEditMode(m, "image-zone");
+    expect(m).toBe("image-zone");
+    m = nextEditMode(m, "image-zone");
+    expect(m).toBe("off");
+  });
+});

Front/client/tests/imp90_export_endpoint.test.ts

@@ -0,0 +1,255 @@
+// IMP-56 (#90) u19 — vitest coverage for the vite POST /api/export
+// middleware and its supporting inlineAssetsAsDataUrls helper.
+//
+// Scope:
+//   1) inlineAssetsAsDataUrls (pure helper):
+//      - no url(assets/...) refs → passthrough.
+//      - single PNG ref → inlined as base64 data: URL with image/png mime.
+//      - multiple refs → all inlined.
+//      - SVG ref → image/svg+xml mime.
+//      - missing asset file → left as-is (no throw, no rewrite).
+//      - data:/http:/ URLs (non-asset) → untouched.
+//   2) handleExportStandalone (POST):
+//      - method != POST → false (chain continues; next middleware may handle).
+//      - invalid JSON / non-object body → 400.
+//      - missing run_id → 400.
+//      - invalid run_id (key gate / path traversal) → 400.
+//      - final.html missing → 404.
+//      - success → 200 with Content-Disposition: attachment; filename=...,
+//        Content-Type: text/html; charset=utf-8, body = inlined HTML.
+//
+// Tests exercise the pure handler with mock req/res — no real vite server.
+
+import { describe, it, expect, beforeEach, afterEach } from "vitest";
+import { EventEmitter } from "node:events";
+import * as fs from "node:fs";
+import * as os from "node:os";
+import * as path from "node:path";
+import {
+  handleExportStandalone,
+  inlineAssetsAsDataUrls,
+} from "../../vite.config";
+
+function makeMockRes() {
+  const state = {
+    statusCode: 0,
+    headers: {} as Record<string, string>,
+    body: "",
+    ended: false,
+  };
+  return {
+    state,
+    res: {
+      writeHead(status: number, headers?: Record<string, string>) {
+        state.statusCode = status;
+        if (headers) state.headers = headers;
+      },
+      end(body?: string) {
+        state.body = body ?? "";
+        state.ended = true;
+      },
+    },
+  };
+}
+
+function makeMockReq(opts: {
+  method?: string;
+}): EventEmitter & { method?: string; send: (body: string) => void } {
+  const ee = new EventEmitter() as EventEmitter & {
+    method?: string;
+    send: (body: string) => void;
+  };
+  ee.method = opts.method;
+  ee.send = (body: string) => {
+    if (body.length > 0) ee.emit("data", Buffer.from(body, "utf-8"));
+    ee.emit("end");
+  };
+  return ee;
+}
+
+function seedRun(
+  daRoot: string,
+  runId: string,
+  htmlBody: string,
+  assets?: Record<string, Buffer | string>,
+): string {
+  const runDir = path.join(daRoot, "data", "runs", runId, "phase_z2");
+  fs.mkdirSync(runDir, { recursive: true });
+  const html = path.join(runDir, "final.html");
+  fs.writeFileSync(html, htmlBody, "utf-8");
+  if (assets) {
+    for (const [rel, buf] of Object.entries(assets)) {
+      const dst = path.join(runDir, "assets", rel);
+      fs.mkdirSync(path.dirname(dst), { recursive: true });
+      fs.writeFileSync(dst, buf);
+    }
+  }
+  return runDir;
+}
+
+describe("inlineAssetsAsDataUrls (IMP-56 #90 u19)", () => {
+  let tmp: string;
+
+  beforeEach(() => {
+    tmp = fs.mkdtempSync(path.join(os.tmpdir(), "imp90-u19-inline-"));
+  });
+
+  afterEach(() => {
+    fs.rmSync(tmp, { recursive: true, force: true });
+  });
+
+  it("returns html unchanged when no url(assets/...) refs are present", () => {
+    const html = "<html><style>body{color:red;}</style><body>hi</body></html>";
+    expect(inlineAssetsAsDataUrls(html, tmp)).toBe(html);
+  });
+
+  it("inlines a single PNG asset as a base64 data: URL with image/png mime", () => {
+    fs.mkdirSync(path.join(tmp, "frame_x"), { recursive: true });
+    const pngBytes = Buffer.from([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a]);
+    fs.writeFileSync(path.join(tmp, "frame_x", "a.png"), pngBytes);
+    const html = "background: url(assets/frame_x/a.png);";
+    const out = inlineAssetsAsDataUrls(html, tmp);
+    expect(out).toContain(`url("data:image/png;base64,${pngBytes.toString("base64")}")`);
+    expect(out).not.toContain("url(assets/frame_x/a.png)");
+  });
+
+  it("inlines multiple refs across the same HTML body", () => {
+    fs.mkdirSync(path.join(tmp, "f"), { recursive: true });
+    fs.writeFileSync(path.join(tmp, "f", "one.png"), Buffer.from("ONE"));
+    fs.writeFileSync(path.join(tmp, "f", "two.png"), Buffer.from("TWO"));
+    const html = "a{background:url(assets/f/one.png)} b{background:url(assets/f/two.png)}";
+    const out = inlineAssetsAsDataUrls(html, tmp);
+    expect(out).toContain(`data:image/png;base64,${Buffer.from("ONE").toString("base64")}`);
+    expect(out).toContain(`data:image/png;base64,${Buffer.from("TWO").toString("base64")}`);
+  });
+
+  it("uses image/svg+xml mime for .svg refs", () => {
+    fs.mkdirSync(path.join(tmp, "f"), { recursive: true });
+    fs.writeFileSync(path.join(tmp, "f", "icon.svg"), "<svg/>", "utf-8");
+    const html = "url(assets/f/icon.svg)";
+    const out = inlineAssetsAsDataUrls(html, tmp);
+    expect(out).toContain("data:image/svg+xml;base64,");
+  });
+
+  it("leaves the ref untouched when the asset file is missing", () => {
+    const html = "url(assets/missing/file.png)";
+    const out = inlineAssetsAsDataUrls(html, tmp);
+    expect(out).toBe(html);
+  });
+
+  it("does not touch data: or http(s): url() values (only matches assets/...)", () => {
+    const html =
+      "x{background:url(data:image/png;base64,AAA)} " +
+      "y{background:url(https://cdn.x/a.png)}";
+    expect(inlineAssetsAsDataUrls(html, tmp)).toBe(html);
+  });
+
+  it("handles quoted url(...) refs (single and double quotes)", () => {
+    fs.mkdirSync(path.join(tmp, "q"), { recursive: true });
+    fs.writeFileSync(path.join(tmp, "q", "k.png"), Buffer.from("K"));
+    const html =
+      "a{background:url('assets/q/k.png')} b{background:url(\"assets/q/k.png\")}";
+    const out = inlineAssetsAsDataUrls(html, tmp);
+    const data = `data:image/png;base64,${Buffer.from("K").toString("base64")}`;
+    expect(out.split(data).length - 1).toBe(2);
+  });
+});
+
+describe("handleExportStandalone (IMP-56 #90 u19)", () => {
+  let daRoot: string;
+
+  beforeEach(() => {
+    daRoot = fs.mkdtempSync(path.join(os.tmpdir(), "imp90-u19-da-"));
+  });
+
+  afterEach(() => {
+    fs.rmSync(daRoot, { recursive: true, force: true });
+  });
+
+  it("returns false (next chained) when method != POST", () => {
+    const req = makeMockReq({ method: "GET" });
+    const { res, state } = makeMockRes();
+    const handled = handleExportStandalone(req, res, daRoot);
+    expect(handled).toBe(false);
+    expect(state.ended).toBe(false);
+  });
+
+  it("returns 400 on invalid JSON body", () => {
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    const handled = handleExportStandalone(req, res, daRoot);
+    expect(handled).toBe(true);
+    req.send("{nope");
+    expect(state.statusCode).toBe(400);
+    expect(JSON.parse(state.body).error).toBe("invalid JSON");
+  });
+
+  it("returns 400 when body is not a JSON object (array root)", () => {
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    handleExportStandalone(req, res, daRoot);
+    req.send(JSON.stringify(["x"]));
+    expect(state.statusCode).toBe(400);
+    expect(JSON.parse(state.body).error).toBe("body must be a JSON object");
+  });
+
+  it("returns 400 when run_id is missing", () => {
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    handleExportStandalone(req, res, daRoot);
+    req.send(JSON.stringify({}));
+    expect(state.statusCode).toBe(400);
+    expect(JSON.parse(state.body).error).toBe("missing run_id");
+  });
+
+  it("returns 400 when run_id contains path traversal", () => {
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    handleExportStandalone(req, res, daRoot);
+    req.send(JSON.stringify({ run_id: "../escape" }));
+    expect(state.statusCode).toBe(400);
+    expect(JSON.parse(state.body).error).toBe("invalid run_id");
+  });
+
+  it("returns 404 when final.html does not exist for run_id", () => {
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    handleExportStandalone(req, res, daRoot);
+    req.send(JSON.stringify({ run_id: "ghost_run" }));
+    expect(state.statusCode).toBe(404);
+    expect(JSON.parse(state.body).error).toBe("final.html not found");
+  });
+
+  it("returns 200 with text/html body + Content-Disposition on success", () => {
+    seedRun(daRoot, "mdx03_run", "<html><body>03</body></html>");
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    handleExportStandalone(req, res, daRoot);
+    req.send(JSON.stringify({ run_id: "mdx03_run" }));
+    expect(state.statusCode).toBe(200);
+    expect(state.headers["Content-Type"]).toBe("text/html; charset=utf-8");
+    expect(state.headers["Content-Disposition"]).toBe(
+      'attachment; filename="mdx03_run.html"',
+    );
+    expect(state.body).toBe("<html><body>03</body></html>");
+  });
+
+  it("inlines assets in final.html when run dir has assets/", () => {
+    const pngBytes = Buffer.from("PNGDATA");
+    seedRun(
+      daRoot,
+      "mdx05_run",
+      "<html><body><div style=\"background: url(assets/f/x.png)\"></div></body></html>",
+      { "f/x.png": pngBytes },
+    );
+    const req = makeMockReq({ method: "POST" });
+    const { res, state } = makeMockRes();
+    handleExportStandalone(req, res, daRoot);
+    req.send(JSON.stringify({ run_id: "mdx05_run" }));
+    expect(state.statusCode).toBe(200);
+    expect(state.body).toContain(
+      `data:image/png;base64,${pngBytes.toString("base64")}`,
+    );
+    expect(state.body).not.toContain("url(assets/f/x.png)");
+  });
+});

Front/client/tests/imp90_structure_overlay.test.tsx

@@ -0,0 +1,150 @@
+// IMP-90 (#90) u14 — vitest coverage for the pure helpers exported by
+// `StructureEditOverlay`. The React component itself is not rendered
+// (jsdom / @testing-library NOT in Front devDependencies — verified in
+// `Front/package.json`); we test the deterministic pieces that drive its
+// JSX: `resolveEffectiveSlotOrder` (effective-order resolution under
+// override) and `moveItem` (immutable reorder primitive).
+//
+// Upstream / downstream contracts (verified by prior units):
+//   - u2  KNOWN_AXES += structure_overrides (Python backend).
+//   - u3  vite allowlist += structure_overrides.
+//   - u6  structure_override_resolver — inner shape locked to
+//         {slot_order, hidden_slots}; frame swap REJECTED to existing
+//         frames axis.
+//   - u10 typed-client `StructureOverridePerZone` + extract helper.
+//   - u15 (next) will debounce + PUT the emitted capture.
+//
+// u14 scope: pure helpers only. React render path is verified by Codex
+// auditor via static read of the JSX (no runtime test possible without
+// jsdom). Tests below are intentionally side-effect-free.
+
+import { describe, it, expect } from "vitest";
+import {
+  resolveEffectiveSlotOrder,
+  moveItem,
+} from "../src/components/StructureEditOverlay";
+
+// ─────────────────────────────────────────────────────────────────────
+// resolveEffectiveSlotOrder
+// ─────────────────────────────────────────────────────────────────────
+
+describe("resolveEffectiveSlotOrder — no override", () => {
+  it("returns a fresh copy of the discovered keys when slotOrder is undefined", () => {
+    const discovered = ["a", "b", "c"];
+    const out = resolveEffectiveSlotOrder(discovered, undefined);
+    expect(out).toEqual(["a", "b", "c"]);
+    expect(out).not.toBe(discovered);
+  });
+  it("returns a fresh copy when slotOrder is null", () => {
+    const out = resolveEffectiveSlotOrder(["a", "b"], null);
+    expect(out).toEqual(["a", "b"]);
+  });
+  it("returns a fresh copy when slotOrder is empty []", () => {
+    const out = resolveEffectiveSlotOrder(["a", "b"], []);
+    expect(out).toEqual(["a", "b"]);
+  });
+  it("handles empty discovered list (no slots in zone)", () => {
+    expect(resolveEffectiveSlotOrder([], undefined)).toEqual([]);
+    expect(resolveEffectiveSlotOrder([], ["x"])).toEqual([]);
+  });
+});
+
+describe("resolveEffectiveSlotOrder — full override", () => {
+  it("reorders all discovered keys per slotOrder", () => {
+    expect(
+      resolveEffectiveSlotOrder(["a", "b", "c"], ["c", "a", "b"]),
+    ).toEqual(["c", "a", "b"]);
+  });
+  it("is idempotent when slotOrder matches discovered order", () => {
+    expect(
+      resolveEffectiveSlotOrder(["a", "b", "c"], ["a", "b", "c"]),
+    ).toEqual(["a", "b", "c"]);
+  });
+});
+
+describe("resolveEffectiveSlotOrder — partial / drift override", () => {
+  it("appends missing discovered keys in backend order at the tail", () => {
+    // user reordered b -> first, but c was added later by backend.
+    expect(
+      resolveEffectiveSlotOrder(["a", "b", "c"], ["b", "a"]),
+    ).toEqual(["b", "a", "c"]);
+  });
+  it("drops override entries that no longer exist in discovered keys", () => {
+    // user had slot 'x' before; backend dropped it.
+    expect(
+      resolveEffectiveSlotOrder(["a", "b"], ["x", "a", "b"]),
+    ).toEqual(["a", "b"]);
+  });
+  it("dedupes duplicate entries within slotOrder", () => {
+    expect(
+      resolveEffectiveSlotOrder(["a", "b", "c"], ["a", "a", "b"]),
+    ).toEqual(["a", "b", "c"]);
+  });
+  it("dedupe + drop + append all together (stress)", () => {
+    expect(
+      resolveEffectiveSlotOrder(
+        ["a", "b", "c", "d"],
+        ["d", "x", "d", "a", "ghost"],
+      ),
+    ).toEqual(["d", "a", "b", "c"]);
+  });
+  it("ignores non-string entries in slotOrder", () => {
+    const bogus = ["a", null as unknown as string, undefined as unknown as string, "b"];
+    expect(resolveEffectiveSlotOrder(["a", "b"], bogus)).toEqual(["a", "b"]);
+  });
+});
+
+// ─────────────────────────────────────────────────────────────────────
+// moveItem
+// ─────────────────────────────────────────────────────────────────────
+
+describe("moveItem — happy paths", () => {
+  it("moves index 0 down by 1 (swap with index 1)", () => {
+    expect(moveItem(["a", "b", "c"], 0, 1)).toEqual(["b", "a", "c"]);
+  });
+  it("moves index 2 up by 1 (swap with index 1)", () => {
+    expect(moveItem(["a", "b", "c"], 2, -1)).toEqual(["a", "c", "b"]);
+  });
+  it("moves across larger delta (swap with target)", () => {
+    expect(moveItem(["a", "b", "c", "d"], 0, 2)).toEqual(["c", "b", "a", "d"]);
+  });
+});
+
+describe("moveItem — bounds", () => {
+  it("no-op (fresh copy) when moving first up", () => {
+    const src = ["a", "b", "c"];
+    const out = moveItem(src, 0, -1);
+    expect(out).toEqual(["a", "b", "c"]);
+    expect(out).not.toBe(src);
+  });
+  it("no-op when moving last down", () => {
+    expect(moveItem(["a", "b", "c"], 2, 1)).toEqual(["a", "b", "c"]);
+  });
+  it("no-op when index negative", () => {
+    expect(moveItem(["a", "b"], -1, 1)).toEqual(["a", "b"]);
+  });
+  it("no-op when index past end", () => {
+    expect(moveItem(["a", "b"], 5, -1)).toEqual(["a", "b"]);
+  });
+  it("no-op when target falls out of range from large delta", () => {
+    expect(moveItem(["a", "b", "c"], 1, 99)).toEqual(["a", "b", "c"]);
+  });
+  it("no-op on empty array (any index)", () => {
+    expect(moveItem<string>([], 0, 1)).toEqual([]);
+  });
+});
+
+describe("moveItem — immutability", () => {
+  it("never mutates the input array", () => {
+    const src = ["a", "b", "c"];
+    moveItem(src, 0, 1);
+    expect(src).toEqual(["a", "b", "c"]);
+  });
+  it("returns a new reference even when no-op", () => {
+    const src = ["a", "b"];
+    expect(moveItem(src, 0, -1)).not.toBe(src);
+  });
+  it("preserves T-typed values (number array)", () => {
+    expect(moveItem([1, 2, 3], 0, 1)).toEqual([2, 1, 3]);
+  });
+});

Front/client/tests/imp90_text_edit_capture.test.tsx

@@ -0,0 +1,259 @@
+// IMP-90 (#90) u13 — vitest coverage for `deriveTextEditCapture`, the pure
+// helper that resolves a contentEditable focusout target into the
+// (zone_id, text_path, value) capture tuple emitted by SlideCanvas.
+//
+// Upstream contract (verified by prior units):
+//   - u8 `src/text_path_stamper.py` stamps `data-text-path="{slot_key}.{
+//     line_index}"` on every rendered text-line opening tag at Step 13.
+//   - u9 wires the stamper into `render_slide` so the final.html consumed
+//     by SlideCanvas's iframe carries those attributes.
+//   - Phase Z slide-base wraps every zone in `.zone[data-zone-position]`
+//     (verified at SlideCanvas.tsx onLoad measure block).
+//
+// u13 scope: derive the capture tuple from any descendant of a stamped
+// line, OR the stamped line itself. Non-stamped targets (slide-base
+// title/footer, decorative spans outside the zone tree) return null so
+// the focusout handler silently skips them — never crashes.
+//
+// Forward-compat note: u15 will debounce + PUT the capture; u15 MUST NOT
+// alter the (target) -> {zoneId, textPath, value} | null contract verified
+// here. Any change to the resolution semantics is a scope-violation
+// against the u13 binding contract.
+//
+// jsdom is NOT in devDependencies (verified in Front/package.json); this
+// test mocks `TextEditCaptureTarget` with structurally-typed objects per
+// the established u11/u12 pure-helper pattern.
+
+import { describe, it, expect } from "vitest";
+import {
+  deriveTextEditCapture,
+  type TextEditCapture,
+  type TextEditCaptureTarget,
+} from "../src/components/SlideCanvas";
+
+// --- minimal closest-aware mock builders -----------------------------
+// Each node only needs to know which selectors it matches and its
+// parent chain — `closest` is implemented by walking parent pointers.
+
+interface MockNodeSpec {
+  matches: string[];
+  attrs?: Record<string, string>;
+  text?: string | null;
+  parent?: MockNode | null;
+}
+interface MockNode extends TextEditCaptureTarget {
+  matches(sel: string): boolean;
+  parent: MockNode | null;
+}
+function makeNode(spec: MockNodeSpec): MockNode {
+  const node: MockNode = {
+    parent: spec.parent ?? null,
+    matches(sel: string) {
+      return spec.matches.includes(sel);
+    },
+    closest(sel: string): TextEditCaptureTarget | null {
+      let cur: MockNode | null = node;
+      while (cur) {
+        if (cur.matches(sel)) return cur;
+        cur = cur.parent;
+      }
+      return null;
+    },
+    getAttribute(name: string): string | null {
+      return spec.attrs?.[name] ?? null;
+    },
+    textContent: spec.text === undefined ? null : spec.text,
+  };
+  return node;
+}
+
+// Canonical zone + line scaffold used across happy-path tests.
+// `null` for any field is preserved verbatim so edge cases (missing attr /
+// null textContent) can exercise the helper's defensive branches.
+function makeZoneLineScaffold(opts: {
+  zoneId?: string | null;
+  textPath?: string | null;
+  lineText?: string | null;
+}) {
+  const zone = makeNode({
+    matches: [".zone[data-zone-position]"],
+    attrs: opts.zoneId === null ? {} : { "data-zone-position": opts.zoneId ?? "top" },
+  });
+  const line = makeNode({
+    matches: ["[data-text-path]"],
+    attrs:
+      opts.textPath === null
+        ? {}
+        : { "data-text-path": opts.textPath ?? "row_1_left_body.0" },
+    text: opts.lineText === undefined ? "hello world" : opts.lineText,
+    parent: zone,
+  });
+  return { zone, line };
+}
+
+describe("deriveTextEditCapture (IMP-90 u13) — null inputs / non-stamped", () => {
+  it("returns null when target is null", () => {
+    expect(deriveTextEditCapture(null)).toBeNull();
+  });
+
+  it("returns null when no ancestor has data-text-path (e.g., slide title)", () => {
+    const title = makeNode({
+      matches: [".slide-title"],
+      text: "Phase Z 슬라이드",
+    });
+    expect(deriveTextEditCapture(title)).toBeNull();
+  });
+
+  it("returns null when the stamped line has no enclosing zone", () => {
+    // Decorative line stamped by the future u8 but rendered outside a
+    // zone (e.g., footer pill). u13 silently skips — caller never sees
+    // a half-resolved capture.
+    const orphanLine = makeNode({
+      matches: ["[data-text-path]"],
+      attrs: { "data-text-path": "footer.0" },
+      text: "결론",
+    });
+    expect(deriveTextEditCapture(orphanLine)).toBeNull();
+  });
+});
+
+describe("deriveTextEditCapture (IMP-90 u13) — happy path", () => {
+  it("resolves (zoneId, textPath, value) when target IS the stamped line", () => {
+    const { line } = makeZoneLineScaffold({
+      zoneId: "top",
+      textPath: "row_1_left_body.0",
+      lineText: "분석 결과",
+    });
+    expect(deriveTextEditCapture(line)).toEqual<TextEditCapture>({
+      zoneId: "top",
+      textPath: "row_1_left_body.0",
+      value: "분석 결과",
+    });
+  });
+
+  it("walks up to the stamped line when target is a nested descendant", () => {
+    const { zone, line } = makeZoneLineScaffold({
+      zoneId: "bottom_l",
+      textPath: "left_body.2",
+      lineText: "wrapped",
+    });
+    // emulate a SPAN inside the stamped line (e.g., bold inline span)
+    const innerSpan = makeNode({
+      matches: ["span.highlight"],
+      text: "ignored — closest walks to the line",
+      parent: line,
+    });
+    void zone;
+    expect(deriveTextEditCapture(innerSpan)).toEqual<TextEditCapture>({
+      zoneId: "bottom_l",
+      textPath: "left_body.2",
+      value: "wrapped",
+    });
+  });
+
+  it("preserves the line's textContent without HTML normalization", () => {
+    const { line } = makeZoneLineScaffold({
+      zoneId: "primary",
+      textPath: "headline.0",
+      lineText: "  spaced   inner   words  ",
+    });
+    // u13 trims outer whitespace but does NOT collapse interior whitespace
+    // — value mirrors what user typed, modulo blur-edge trim.
+    expect(deriveTextEditCapture(line)?.value).toBe("spaced   inner   words");
+  });
+
+  it("returns empty string when textContent is null (edge: empty line)", () => {
+    const { line } = makeZoneLineScaffold({
+      zoneId: "top",
+      textPath: "row_1_left_body.0",
+      lineText: null,
+    });
+    expect(deriveTextEditCapture(line)?.value).toBe("");
+  });
+
+  it("returns empty string when textContent is whitespace-only", () => {
+    const { line } = makeZoneLineScaffold({
+      zoneId: "top",
+      textPath: "row_1_left_body.0",
+      lineText: "   \n  \t  ",
+    });
+    expect(deriveTextEditCapture(line)?.value).toBe("");
+  });
+});
+
+describe("deriveTextEditCapture (IMP-90 u13) — missing attribute defensiveness", () => {
+  it("returns null when data-text-path attribute is absent on the matched line", () => {
+    // Should not happen with the u8 stamper, but a downstream mutation
+    // (e.g., user pasting a fresh element) could create a stamped-class
+    // node without the actual attribute. u13 stays defensive.
+    const zone = makeNode({
+      matches: [".zone[data-zone-position]"],
+      attrs: { "data-zone-position": "top" },
+    });
+    const lineNoPath = makeNode({
+      matches: ["[data-text-path]"],
+      attrs: {},
+      text: "hello",
+      parent: zone,
+    });
+    expect(deriveTextEditCapture(lineNoPath)).toBeNull();
+  });
+
+  it("returns null when data-zone-position attribute is absent on the matched zone", () => {
+    const zoneNoId = makeNode({
+      matches: [".zone[data-zone-position]"],
+      attrs: {},
+    });
+    const line = makeNode({
+      matches: ["[data-text-path]"],
+      attrs: { "data-text-path": "row_1_left_body.0" },
+      text: "hello",
+      parent: zoneNoId,
+    });
+    expect(deriveTextEditCapture(line)).toBeNull();
+  });
+});
+
+describe("deriveTextEditCapture (IMP-90 u13) — referential transparency", () => {
+  it("multiple calls with the same target return equal captures", () => {
+    const { line } = makeZoneLineScaffold({
+      zoneId: "top",
+      textPath: "row_1_left_body.0",
+      lineText: "stable",
+    });
+    const a = deriveTextEditCapture(line);
+    const b = deriveTextEditCapture(line);
+    expect(a).toEqual(b);
+    expect(a).not.toBe(b); // fresh objects each call (caller-friendly)
+  });
+
+  it("does not mutate the target element (attrs / parent / textContent unchanged)", () => {
+    const { line, zone } = makeZoneLineScaffold({
+      zoneId: "top",
+      textPath: "row_1_left_body.0",
+      lineText: "immutable",
+    });
+    deriveTextEditCapture(line);
+    expect(line.getAttribute("data-text-path")).toBe("row_1_left_body.0");
+    expect(line.textContent).toBe("immutable");
+    expect(zone.getAttribute("data-zone-position")).toBe("top");
+  });
+});
+
+describe("deriveTextEditCapture (IMP-90 u13) — zone id pass-through", () => {
+  // u13 does not validate the zone id shape — Phase Z slide-base owns the
+  // canonical zone position vocabulary, and u15 / pipeline-side resolver
+  // (u4) re-validate downstream. u13 just forwards whatever the stamped
+  // DOM declared.
+  const ZONE_IDS = ["top", "bottom_l", "bottom_r", "primary", "secondary"];
+  it.each(ZONE_IDS)("preserves zone id '%s' verbatim", (zid) => {
+    const { line } = makeZoneLineScaffold({
+      zoneId: zid,
+      textPath: `${zid}.0`,
+      lineText: "x",
+    });
+    const cap = deriveTextEditCapture(line);
+    expect(cap?.zoneId).toBe(zid);
+    expect(cap?.textPath).toBe(`${zid}.0`);
+  });
+});

Front/client/tests/user_overrides_endpoint.test.ts

@@ -305,23 +305,37 @@ describe("handleGetUserOverrides (IMP-52 u3)", () => {
 // IMP-52 u4 — PUT endpoint coverage
 // ---------------------------------------------------------------------------
 
-describe("KNOWN_USER_OVERRIDES_AXES (IMP-52 u4)", () => {
+describe("KNOWN_USER_OVERRIDES_AXES (IMP-52 u4 + IMP-56 #90 u3 allowlist sync)", () => {
   it("matches the Python KNOWN_AXES tuple in src/user_overrides_io.py", () => {
     // The on-disk schema is shared with backend pipeline fallback (u2).
     // Any drift here means a PUT could write an axis that the Python
     // load() ignores, or vice-versa, silently losing user overrides.
-    // Mirror is Python-minus-`slide_css` (known IMP-45 #74 gap — the
-    // frontend never writes slide_css). IMP-55 #93 u1 adds the bool
-    // `manual_section_assignment` axis as a first-class allowlist entry.
+    // IMP-56 #90 u3 closes the prior `slide_css` gap (IMP-45 #74) and
+    // pre-wires `text_overrides` (IMP-56 #90 u1) +
+    // `structure_overrides` (IMP-56 #90 u2) — full 9-axis mirror of the
+    // Python tuple, same order.
     expect(KNOWN_USER_OVERRIDES_AXES).toEqual([
       "layout",
       "zone_geometries",
       "zone_sections",
       "frames",
       "image_overrides",
+      "slide_css",
       "manual_section_assignment",
+      "text_overrides",
+      "structure_overrides",
     ]);
   });
+
+  it("includes the 3 axes added by IMP-56 #90 u3 (allowlist sync)", () => {
+    // Spot-check the diff in addition to the full-equality assertion so a
+    // future edit that drops one of the new axes fails with a localized
+    // error rather than a 9-vs-N tuple-diff that obscures intent.
+    expect(KNOWN_USER_OVERRIDES_AXES).toContain("slide_css");
+    expect(KNOWN_USER_OVERRIDES_AXES).toContain("text_overrides");
+    expect(KNOWN_USER_OVERRIDES_AXES).toContain("structure_overrides");
+    expect(KNOWN_USER_OVERRIDES_AXES.length).toBe(9);
+  });
 });
 
 describe("mergeUserOverrides (IMP-55 #93 u1) — manual_section_assignment bool axis", () => {

Front/client/tests/user_overrides_restore.test.ts

@@ -35,6 +35,8 @@ import {
   deriveUserOverridesKey,
   remapPersistedFramesToZoneFrames,
   saveImageOverride,
+  saveTextOverride,
+  saveStructureOverride,
 } from "../src/utils/slidePlanUtils";
 
 // ─── Fixtures ───────────────────────────────────────────────────────────────
@@ -59,6 +61,11 @@ function makeSelection(overrides?: Partial<UserSelection["overrides"]>): UserSel
       // pre-existing fixture matches the `createInitialUserSelection` seed
       // and stays compile-clean after u3 widened the type.
       manual_section_assignment: false,
+      // IMP-56 (#90) u15 — keep the fixture in sync with the two Step-22
+      // persist axes declared on `UserSelection.overrides`. Empty by
+      // default so pre-existing cases retain their shape.
+      text_overrides: {},
+      structure_overrides: {},
       ...overrides,
     },
   };
@@ -550,3 +557,150 @@ describe("manual_section_assignment axis — applyPersistedNonFrameOverrides (IM
     expect(next.overrides.manual_section_assignment).toBe(true);
   });
 });
+
+// ─── IMP-56 (#90) u15 — text_overrides + structure_overrides axes ───────────
+// Pure helpers wired by Home.tsx into the SlideCanvas u13 focusout capture
+// (text) and u14 structure overlay emit (structure). Tests cover:
+//   • saveTextOverride / saveStructureOverride immutability + merge semantics
+//   • createInitialUserSelection seeding the two new axes empty
+//   • applyPersistedNonFrameOverrides layering via the u10 extract helpers
+
+describe("text_overrides axis — saveTextOverride (IMP-56 u15)", () => {
+  it("records a fresh (zoneId, textPath, value) tuple", () => {
+    const sel = makeSelection();
+    const next = saveTextOverride(sel, "top", "row_1_left_body.0", "분석 결과");
+    expect(next.overrides.text_overrides).toEqual({
+      top: { "row_1_left_body.0": "분석 결과" },
+    });
+  });
+
+  it("merges within the same zone without erasing prior text_paths", () => {
+    const sel = makeSelection({
+      text_overrides: { top: { "row_1_left_body.0": "기존" } },
+    });
+    const next = saveTextOverride(sel, "top", "row_1_left_body.1", "신규");
+    expect(next.overrides.text_overrides.top).toEqual({
+      "row_1_left_body.0": "기존",
+      "row_1_left_body.1": "신규",
+    });
+  });
+
+  it("overwrites the same textPath value within a zone", () => {
+    const sel = makeSelection({
+      text_overrides: { top: { "headline.0": "v1" } },
+    });
+    const next = saveTextOverride(sel, "top", "headline.0", "v2");
+    expect(next.overrides.text_overrides.top).toEqual({ "headline.0": "v2" });
+  });
+
+  it("does not mutate the input selection (immutable contract)", () => {
+    const sel = makeSelection({
+      text_overrides: { top: { "headline.0": "before" } },
+    });
+    saveTextOverride(sel, "top", "headline.0", "after");
+    expect(sel.overrides.text_overrides).toEqual({
+      top: { "headline.0": "before" },
+    });
+  });
+
+  it("seeds an empty text_overrides on a fresh selection", () => {
+    const sel = createInitialUserSelection();
+    expect(sel.overrides.text_overrides).toEqual({});
+  });
+});
+
+describe("structure_overrides axis — saveStructureOverride (IMP-56 u15)", () => {
+  it("records a fresh (zoneId → {slot_order, hidden_slots}) tuple", () => {
+    const sel = makeSelection();
+    const next = saveStructureOverride(sel, "top", {
+      slot_order: ["b", "a"],
+      hidden_slots: ["c"],
+    });
+    expect(next.overrides.structure_overrides).toEqual({
+      top: { slot_order: ["b", "a"], hidden_slots: ["c"] },
+    });
+  });
+
+  it("replaces an existing zone entry verbatim (no merge within zone)", () => {
+    const sel = makeSelection({
+      structure_overrides: { top: { slot_order: ["a", "b"], hidden_slots: [] } },
+    });
+    const next = saveStructureOverride(sel, "top", {
+      slot_order: ["b", "a"],
+      hidden_slots: ["a"],
+    });
+    expect(next.overrides.structure_overrides.top).toEqual({
+      slot_order: ["b", "a"],
+      hidden_slots: ["a"],
+    });
+  });
+
+  it("keeps unrelated zones intact when updating one zone", () => {
+    const sel = makeSelection({
+      structure_overrides: {
+        top: { slot_order: ["x"], hidden_slots: [] },
+        bottom_l: { slot_order: ["y"], hidden_slots: ["z"] },
+      },
+    });
+    const next = saveStructureOverride(sel, "top", {
+      slot_order: ["x", "x2"],
+      hidden_slots: [],
+    });
+    expect(next.overrides.structure_overrides.bottom_l).toEqual({
+      slot_order: ["y"],
+      hidden_slots: ["z"],
+    });
+  });
+
+  it("does not mutate the input perZone object after save", () => {
+    const sel = makeSelection();
+    const perZone = { slot_order: ["a"], hidden_slots: ["b"] };
+    const next = saveStructureOverride(sel, "top", perZone);
+    perZone.slot_order.push("MUTATED");
+    expect(next.overrides.structure_overrides.top.slot_order).toEqual(["a"]);
+  });
+
+  it("seeds an empty structure_overrides on a fresh selection", () => {
+    const sel = createInitialUserSelection();
+    expect(sel.overrides.structure_overrides).toEqual({});
+  });
+});
+
+describe("Step-22 axes — applyPersistedNonFrameOverrides restore (IMP-56 u15)", () => {
+  it("layers persisted text_overrides through the u10 extract helper", () => {
+    const sel = makeSelection();
+    const next = applyPersistedNonFrameOverrides(sel, {
+      text_overrides: {
+        top: { "row_1_left_body.0": "복원" },
+      },
+    });
+    expect(next.overrides.text_overrides).toEqual({
+      top: { "row_1_left_body.0": "복원" },
+    });
+  });
+
+  it("layers persisted structure_overrides through the u10 extract helper", () => {
+    const sel = makeSelection();
+    const next = applyPersistedNonFrameOverrides(sel, {
+      structure_overrides: {
+        top: { slot_order: ["b", "a"], hidden_slots: ["c"] },
+      },
+    });
+    expect(next.overrides.structure_overrides).toEqual({
+      top: { slot_order: ["b", "a"], hidden_slots: ["c"] },
+    });
+  });
+
+  it("drops non-object payloads silently (no throw, axis stays empty)", () => {
+    const sel = makeSelection();
+    const next = applyPersistedNonFrameOverrides(sel, {
+      text_overrides: "garbage" as unknown as Record<string, Record<string, string>>,
+      structure_overrides: ["bad"] as unknown as Record<
+        string,
+        { slot_order?: string[]; hidden_slots?: string[] }
+      >,
+    });
+    expect(next.overrides.text_overrides).toEqual({});
+    expect(next.overrides.structure_overrides).toEqual({});
+  });
+});

Front/vite.config.ts

@@ -219,25 +219,36 @@ function vitePluginStorageProxy(): Plugin {
 
 export const USER_OVERRIDES_KEY_RE = /^[A-Za-z0-9_][A-Za-z0-9_.\-]*$/;
 
-// The six in-scope axes — mirror of KNOWN_AXES in
-// src/user_overrides_io.py minus `slide_css` (known gap, IMP-45 #74 —
-// the Python side persists it for backend consumption; the Vite PUT does
-// not write it because the frontend never mutates the slide-level CSS
-// override). Any payload key outside this allowlist is silently dropped
-// by the PUT handler (u4) so the on-disk schema cannot drift from the
-// backend pipeline (u2) contract. Foreign top-level keys already on disk
-// are preserved verbatim (see mergeUserOverrides).
+// The nine in-scope axes — full mirror of KNOWN_AXES in
+// src/user_overrides_io.py. Order matches the Python tuple verbatim so
+// a side-by-side audit reads as a no-op. Any payload key outside this
+// allowlist is silently dropped by the PUT handler (u4) so the on-disk
+// schema cannot drift from the backend pipeline (u2) contract. Foreign
+// top-level keys already on disk are preserved verbatim (see
+// mergeUserOverrides).
 // IMP-51 (#79) u2: added `image_overrides` (image_id → {x,y,w,h}
 // percent-of-slide coordinates).
 // IMP-55 (#93) u1: added `manual_section_assignment` (bool intent marker
 // — drag-drop sets true, layout apply/cancel sets false).
+// IMP-56 (#90) u3: allowlist sync — closes the prior `slide_css` gap
+// (IMP-45 #74; the Step-22 slide CSS edit path will write it from the
+// frontend) and pre-wires `text_overrides` (IMP-56 #90 u1, keyed by
+// {zone_id: {text_path: value}}) + `structure_overrides` (IMP-56 #90 u2,
+// keyed by {zone_id: {slot_order, hidden_slots}} — scope LOCKED to slot
+// reorder + hide; frame swap stays on the existing `frames` axis to
+// preserve Phase Z's no-AI-HTML-structure invariant) so the Step-22
+// capture path (u10~u17) can PUT either axis without a follow-on
+// allowlist edit.
 export const KNOWN_USER_OVERRIDES_AXES = [
   "layout",
   "zone_geometries",
   "zone_sections",
   "frames",
   "image_overrides",
+  "slide_css",
   "manual_section_assignment",
+  "text_overrides",
+  "structure_overrides",
 ] as const;
 export type KnownUserOverridesAxis = (typeof KNOWN_USER_OVERRIDES_AXES)[number];
 
@@ -506,6 +517,211 @@ export function handlePutUserOverrides(
   return true;
 }
 
+// =============================================================================
+// IMP-56 (#90) u18 — POST /api/connect : cel astro dev mirror copy.
+//
+// Body: {"run_id": "<id>", "slug": "<mdx-stem>"}.
+//   • Copies <DESIGN_AGENT_ROOT>/data/runs/<run_id>/phase_z2/final.html →
+//     <CEL_PROJECT_ROOT>/public/slides/<slug>.html (overwrite).
+//   • If <run_dir>/phase_z2/assets/ exists, mirrors its contents into
+//     <CEL_PROJECT_ROOT>/public/slides/assets/ (overwrite copy, recursive).
+//   • run_id and slug are validated through the existing
+//     isValidUserOverridesKey gate so path-traversal payloads are rejected.
+// =============================================================================
+
+export function mirrorDirRecursive(srcDir: string, dstDir: string): number {
+  if (!fs.existsSync(srcDir) || !fs.statSync(srcDir).isDirectory()) return 0;
+  if (!fs.existsSync(dstDir)) fs.mkdirSync(dstDir, { recursive: true });
+  let count = 0;
+  for (const entry of fs.readdirSync(srcDir, { withFileTypes: true })) {
+    const srcPath = path.join(srcDir, entry.name);
+    const dstPath = path.join(dstDir, entry.name);
+    if (entry.isDirectory()) {
+      count += mirrorDirRecursive(srcPath, dstPath);
+    } else if (entry.isFile()) {
+      fs.copyFileSync(srcPath, dstPath);
+      count += 1;
+    }
+  }
+  return count;
+}
+
+export function handleConnectMirror(
+  req: PutReqLike,
+  res: ResLike,
+  designAgentRoot: string,
+  celRoot: string,
+): boolean {
+  if (req.method !== "POST") return false;
+  let body = "";
+  req.on("data", (chunk: Buffer | string) => {
+    body += typeof chunk === "string" ? chunk : chunk.toString();
+  });
+  req.on("end", () => {
+    let parsed: unknown;
+    try {
+      parsed = body.length > 0 ? JSON.parse(body) : {};
+    } catch {
+      res.writeHead(400, { "Content-Type": "application/json; charset=utf-8" });
+      res.end(JSON.stringify({ error: "invalid JSON" }));
+      return;
+    }
+    if (typeof parsed !== "object" || parsed === null || Array.isArray(parsed)) {
+      res.writeHead(400, { "Content-Type": "application/json; charset=utf-8" });
+      res.end(JSON.stringify({ error: "body must be a JSON object" }));
+      return;
+    }
+    const { run_id, slug } = parsed as { run_id?: unknown; slug?: unknown };
+    if (typeof run_id !== "string" || typeof slug !== "string") {
+      res.writeHead(400, { "Content-Type": "application/json; charset=utf-8" });
+      res.end(JSON.stringify({ error: "missing run_id or slug" }));
+      return;
+    }
+    if (!isValidUserOverridesKey(run_id) || !isValidUserOverridesKey(slug)) {
+      res.writeHead(400, { "Content-Type": "application/json; charset=utf-8" });
+      res.end(JSON.stringify({ error: "invalid run_id or slug" }));
+      return;
+    }
+    const runDir = path.join(designAgentRoot, "data", "runs", run_id, "phase_z2");
+    const srcHtml = path.join(runDir, "final.html");
+    if (!fs.existsSync(srcHtml)) {
+      res.writeHead(404, { "Content-Type": "application/json; charset=utf-8" });
+      res.end(JSON.stringify({ error: "final.html not found" }));
+      return;
+    }
+    const dstSlidesDir = path.join(celRoot, "public", "slides");
+    if (!fs.existsSync(dstSlidesDir)) fs.mkdirSync(dstSlidesDir, { recursive: true });
+    const dstHtml = path.join(dstSlidesDir, `${slug}.html`);
+    try {
+      fs.copyFileSync(srcHtml, dstHtml);
+    } catch (err) {
+      res.writeHead(500, { "Content-Type": "application/json; charset=utf-8" });
+      res.end(JSON.stringify({ error: `copy failed: ${String(err)}` }));
+      return;
+    }
+    const assetsCopied = mirrorDirRecursive(
+      path.join(runDir, "assets"),
+      path.join(dstSlidesDir, "assets"),
+    );
+    res.writeHead(200, { "Content-Type": "application/json; charset=utf-8" });
+    res.end(JSON.stringify({ success: true, run_id, slug, html_target: dstHtml, assets_copied: assetsCopied }));
+  });
+  req.on("error", () => {
+    res.writeHead(500, { "Content-Type": "application/json; charset=utf-8" });
+    res.end(JSON.stringify({ error: "request error" }));
+  });
+  return true;
+}
+
+// =============================================================================
+// IMP-56 (#90) u19 — POST /api/export : standalone HTML download.
+//
+// Body: {"run_id": "<id>"}.
+//   • Reads <DESIGN_AGENT_ROOT>/data/runs/<run_id>/phase_z2/final.html.
+//   • Inlines every `url(assets/<frame>/<file>)` reference (the only
+//     external dep emitted by the Phase Z2 render path — verified by grep
+//     against templates/phase_z2/slide_base.html and a representative run)
+//     as a base64 data URL so the emitted HTML is portable (file:// open
+//     or any external host, no co-located assets/ dir required). Mirrors
+//     u18 validation: isValidUserOverridesKey gate for path-traversal
+//     rejection; final.html missing → 404.
+//   • Response: 200 text/html with Content-Disposition: attachment so the
+//     browser triggers a download with `<run_id>.html` filename. Raw HTML
+//     body (NOT JSON-wrapped) — the BottomActions wiring (u20) will pipe
+//     the response body straight into a Blob → a[download] click chain
+//     mirroring the existing serializeSlidePlan JSON download flow.
+// =============================================================================
+
+export function inlineAssetsAsDataUrls(html: string, assetsRoot: string): string {
+  // Match `url(assets/<rel-path>)` (with optional single/double quotes,
+  // optional surrounding whitespace). The Phase Z2 render path emits
+  // `url(assets/<frame>/<file>.png)` verbatim into inline `style="..."`
+  // custom-property declarations (see slide_base.html `--card-frame-bg`
+  // etc.) — there is no `<link rel="stylesheet">` or `<img src>` external
+  // ref to handle. Keeping the matcher narrow avoids accidentally
+  // rewriting `data:` / `http(s):` / sibling-path URLs that the render
+  // path does not produce.
+  const URL_RE = /url\(\s*(['"]?)assets\/([^)'"]+)\1\s*\)/g;
+  return html.replace(URL_RE, (match, _quote: string, rel: string) => {
+    const filePath = path.join(assetsRoot, rel);
+    if (!fs.existsSync(filePath) || !fs.statSync(filePath).isFile()) return match;
+    const ext = path.extname(filePath).toLowerCase().slice(1);
+    const mime =
+      ext === "png" ? "image/png" :
+      ext === "jpg" || ext === "jpeg" ? "image/jpeg" :
+      ext === "svg" ? "image/svg+xml" :
+      ext === "webp" ? "image/webp" :
+      ext === "gif" ? "image/gif" :
+      "application/octet-stream";
+    const buf = fs.readFileSync(filePath);
+    return `url("data:${mime};base64,${buf.toString("base64")}")`;
+  });
+}
+
+export function handleExportStandalone(
+  req: PutReqLike,
+  res: ResLike,
+  designAgentRoot: string,
+): boolean {
+  if (req.method !== "POST") return false;
+  let body = "";
+  req.on("data", (chunk: Buffer | string) => {
+    body += typeof chunk === "string" ? chunk : chunk.toString();
+  });
+  req.on("end", () => {
+    let parsed: unknown;
+    try {
+      parsed = body.length > 0 ? JSON.parse(body) : {};
+    } catch {
+      res.writeHead(400, { "Content-Type": "application/json; charset=utf-8" });
+      res.end(JSON.stringify({ error: "invalid JSON" }));
+      return;
+    }
+    if (typeof parsed !== "object" || parsed === null || Array.isArray(parsed)) {
+      res.writeHead(400, { "Content-Type": "application/json; charset=utf-8" });
+      res.end(JSON.stringify({ error: "body must be a JSON object" }));
+      return;
+    }
+    const { run_id } = parsed as { run_id?: unknown };
+    if (typeof run_id !== "string") {
+      res.writeHead(400, { "Content-Type": "application/json; charset=utf-8" });
+      res.end(JSON.stringify({ error: "missing run_id" }));
+      return;
+    }
+    if (!isValidUserOverridesKey(run_id)) {
+      res.writeHead(400, { "Content-Type": "application/json; charset=utf-8" });
+      res.end(JSON.stringify({ error: "invalid run_id" }));
+      return;
+    }
+    const runDir = path.join(designAgentRoot, "data", "runs", run_id, "phase_z2");
+    const srcHtml = path.join(runDir, "final.html");
+    if (!fs.existsSync(srcHtml)) {
+      res.writeHead(404, { "Content-Type": "application/json; charset=utf-8" });
+      res.end(JSON.stringify({ error: "final.html not found" }));
+      return;
+    }
+    let html: string;
+    try {
+      html = fs.readFileSync(srcHtml, "utf-8");
+    } catch (err) {
+      res.writeHead(500, { "Content-Type": "application/json; charset=utf-8" });
+      res.end(JSON.stringify({ error: `read failed: ${String(err)}` }));
+      return;
+    }
+    const inlined = inlineAssetsAsDataUrls(html, path.join(runDir, "assets"));
+    res.writeHead(200, {
+      "Content-Type": "text/html; charset=utf-8",
+      "Content-Disposition": `attachment; filename="${run_id}.html"`,
+    });
+    res.end(inlined);
+  });
+  req.on("error", () => {
+    res.writeHead(500, { "Content-Type": "application/json; charset=utf-8" });
+    res.end(JSON.stringify({ error: "request error" }));
+  });
+  return true;
+}
+
 // =============================================================================
 // Phase Z API Plugin — MDX 업로드 → 파이프라인 실행 → 결과 노출
 //
@@ -514,14 +730,19 @@ export function handlePutUserOverrides(
 //   GET  /data/runs/{run_id}/{path}  →  {DESIGN_AGENT_ROOT}/data/runs/{run_id}/phase_z2/{path}
 //   GET  /api/user-overrides/{key}   →  data/user_overrides/{key}.json (IMP-52 u3)
 //   PUT  /api/user-overrides/{key}   →  partial-merge save (IMP-52 u4)
+//   POST /api/connect                →  cel mirror (IMP-56 #90 u18)
+//   POST /api/export                 →  standalone HTML download (IMP-56 #90 u19)
 //
 // 환경 변수 (선택) :
 //   DESIGN_AGENT_ROOT  python pipeline 실행 cwd. default = D:/ad-hoc/kei/design_agent
+//   CEL_PROJECT_ROOT   cel astro dev repo root. default = D:/ad-hoc/cel
 // =============================================================================
 
 function vitePluginPhaseZApi(): Plugin {
   const DESIGN_AGENT_ROOT =
     process.env.DESIGN_AGENT_ROOT || "D:\\ad-hoc\\kei\\design_agent";
+  const CEL_PROJECT_ROOT =
+    process.env.CEL_PROJECT_ROOT || "D:\\ad-hoc\\cel";
   const UPLOADS_DIR = path.join(DESIGN_AGENT_ROOT, "samples", "uploads");
   const RUNS_DIR = path.join(DESIGN_AGENT_ROOT, "data", "runs");
 
@@ -801,6 +1022,27 @@ function vitePluginPhaseZApi(): Plugin {
         next();
       });
 
+      // ── POST /api/connect → cel astro public/slides mirror ──
+      // IMP-56 (#90) u18 — see handleConnectMirror docblock for body shape +
+      // copy semantics. Logic lives in the pure helper so vitest can drive
+      // it without booting vite.
+      server.middlewares.use("/api/connect", (req, res, next) => {
+        if (handleConnectMirror(req, res, DESIGN_AGENT_ROOT, CEL_PROJECT_ROOT)) return;
+        next();
+      });
+
+      // ── POST /api/export → standalone HTML download ──
+      // IMP-56 (#90) u19 — see handleExportStandalone docblock for body
+      // shape + inline-asset semantics. Logic lives in the pure helper
+      // (handleExportStandalone + inlineAssetsAsDataUrls) so vitest can
+      // drive it without booting vite. The response is raw text/html
+      // (Content-Disposition: attachment); the u20 BottomActions wiring
+      // will turn the response body into a Blob → a[download] click.
+      server.middlewares.use("/api/export", (req, res, next) => {
+        if (handleExportStandalone(req, res, DESIGN_AGENT_ROOT)) return;
+        next();
+      });
+
       // ── GET /data/runs/{run_id}/{path} →  {RUNS_DIR}/{run_id}/phase_z2/{path} ──
       server.middlewares.use("/data/runs", (req, res, next) => {
         if (req.method !== "GET") return next();

src/phase_z2_pipeline.py

@@ -109,6 +109,32 @@ from src.phase_z2_ai_fallback.step17 import run_step17_popup_gate
 # WRITE the snapshot — restore wiring lands in u4.
 from src.phase_z2_reuse_snapshot import build_snapshot, SNAPSHOT_FILENAME
 
+# IMP-56 (#90) u5 — Step 12 text_overrides apply. Pure deterministic; no AI.
+# u4 resolver imports are aliased with leading-underscore so the helper at
+# `_apply_text_overrides_to_zones` reads as a pipeline-private wrapper
+# (mirrors the AI-repair u5 / image-overrides u7 wrapper naming pattern).
+from src.text_override_resolver import (
+    apply_text_override as _apply_text_override,
+    validate_text_overrides as _validate_text_overrides,
+    InvalidTextOverride as _InvalidTextOverride,
+)
+# IMP-56 (#90) u7 — Step 12 structure_overrides apply. Pure deterministic; no AI.
+# u6 resolver imports are aliased with leading-underscore so the helper at
+# `_apply_structure_overrides_to_zones` reads as a pipeline-private wrapper
+# (mirrors the u5 text_overrides wrapper naming pattern). SCOPE LOCKED to
+# slot_order + hidden_slots — frame swap stays on the existing `frames`
+# axis to preserve Phase Z's no-AI-HTML-structure invariant.
+from src.structure_override_resolver import (
+    apply_structure_override as _apply_structure_override,
+    validate_structure_overrides as _validate_structure_overrides,
+)
+# IMP-56 (#90) u9 — Step 13 text_path stamping wired into render_slide.
+# u8 stamper injects ``data-text-path="{slot_key}.{line_index}"`` onto each
+# ``text-line`` opening tag so the frontend SlideCanvas (u10+) can attribute
+# per-line edits back to the ``text_overrides`` axis (u1 schema, u4 resolver,
+# u5 Step-12 apply). Pure deterministic; no AI / HTTP / subprocess.
+from src.text_path_stamper import stamp_zone_html as _stamp_zone_html
+
 
 # ─── Constants ──────────────────────────────────────────────────
 
@@ -882,6 +908,102 @@ def _apply_ai_repair_proposals_to_zones(
         record["apply_status"] = "applied:partial_overrides"
 
 
+def _apply_text_overrides_to_zones(
+    text_overrides: dict,
+    zones_data: list[dict],
+) -> dict:
+    """IMP-56 (#90) u5 — Apply persisted ``text_overrides`` to Step 12 zones.
+
+    Captures the audit shape the Step 12 ``text_overrides`` artifact emits
+    so reviewers can see which user text edits re-applied to the next render
+    and which silently skipped (stale ``text_path`` after a frame swap /
+    layout regression). Per-entry tolerant by design — mirrors the
+    ``image_overrides`` u7 contract so a single malformed row never blocks
+    a batch (Phase Z PZ-4 "no silent shrink" — surface, don't drop).
+
+    raw_content preservation : the function mutates ``zone["slot_payload"]``
+    in place only — ``debug_zones[i].source_section_ids`` and the
+    ``MdxSection`` graph live elsewhere and stay byte-identical. This honours
+    the Stage 1 binding contract ("raw_content preserved at Step 12") and
+    the global no-silent-shrink rule (PZ-4).
+    """
+    sanitized = _validate_text_overrides(text_overrides or {})
+    applied = 0
+    skipped = 0
+    per_zone: list[dict] = []
+    for zone in zones_data:
+        zone_id = zone.get("position")
+        if not isinstance(zone_id, str) or zone_id not in sanitized:
+            continue
+        slot_payload = zone.get("slot_payload")
+        if not isinstance(slot_payload, dict):
+            continue
+        z_applied = 0
+        z_skipped = 0
+        for text_path, value in sanitized[zone_id].items():
+            try:
+                ok = _apply_text_override(slot_payload, text_path, value)
+            except _InvalidTextOverride:
+                ok = False
+            if ok:
+                z_applied += 1
+            else:
+                z_skipped += 1
+        applied += z_applied
+        skipped += z_skipped
+        per_zone.append({
+            "position": zone_id,
+            "applied": z_applied,
+            "skipped": z_skipped,
+        })
+    return {"applied": applied, "skipped": skipped, "per_zone": per_zone}
+
+
+def _apply_structure_overrides_to_zones(
+    structure_overrides: dict,
+    zones_data: list[dict],
+) -> dict:
+    """IMP-56 (#90) u7 — Apply persisted ``structure_overrides`` at Step 12.
+
+    SCOPE LOCK : only top-level ``slot_payload`` key membership + ordering
+    is mutated (reorder + hide). NO DOM rebuild. NO frame swap — the u6
+    validate gate drops any non-``slot_order`` / non-``hidden_slots`` inner
+    key silently. Frame swap stays on the existing ``frames`` axis.
+
+    Per-zone tolerant — stale slot_keys (frame swap / layout regression
+    between renders) silently no-op via ``apply_structure_override``'s
+    ``False`` return (counted as ``skipped_zones``).
+
+    raw_content preservation : per-slot ``list[str]`` line content is
+    NEVER inspected or modified here — the resolver only reorders /
+    removes top-level slot_payload keys. ``debug_zones[i].source_section_ids``
+    + the ``MdxSection`` graph stay byte-identical (mirrors the u5 wiring
+    invariant + Stage 1 binding contract).
+    """
+    sanitized = _validate_structure_overrides(structure_overrides or {})
+    applied_zones = 0
+    skipped_zones = 0
+    per_zone: list[dict] = []
+    for zone in zones_data:
+        zone_id = zone.get("position")
+        if not isinstance(zone_id, str) or zone_id not in sanitized:
+            continue
+        slot_payload = zone.get("slot_payload")
+        if not isinstance(slot_payload, dict):
+            continue
+        mutated = _apply_structure_override(slot_payload, sanitized[zone_id])
+        if mutated:
+            applied_zones += 1
+        else:
+            skipped_zones += 1
+        per_zone.append({"position": zone_id, "mutated": mutated})
+    return {
+        "applied_zones": applied_zones,
+        "skipped_zones": skipped_zones,
+        "per_zone": per_zone,
+    }
+
+
 def _check_post_ai_coverage_invariant(
     units,
     ai_repair_records: list[dict],
@@ -3131,7 +3253,14 @@ def render_slide(slide_title: str, slide_footer: Optional[str],
             rendered_partial,
             f"zones_data[{zone_index}] template_id={template_id!r}",
         )
-        zone["partial_html"] = rendered_partial
+        # IMP-56 (#90) u9 — Step 13 text_path stamp (u8 stamper, pure
+        # deterministic). Injects ``data-text-path="{slot_key}.{line_index}"``
+        # onto each ``text-line`` opening tag so the frontend SlideCanvas
+        # (u10+) can attribute per-line edits back to the text_overrides
+        # axis. Idempotent + forward-compat: non-list slots are silently
+        # skipped, excess text-lines pass through unstamped, and an
+        # already-stamped element is left unchanged.
+        zone["partial_html"] = _stamp_zone_html(rendered_partial, slot_payload)
 
     base = env.get_template("slide_base.html")
     rendered_base = base.render(
@@ -4889,6 +5018,8 @@ def run_phase_z2_mvp1(
     override_section_assignments: Optional[dict[str, list[str]]] = None,
     override_image_overrides: Optional[dict[str, dict]] = None,
     override_slide_css: Optional[str] = None,
+    override_text_overrides: Optional[dict[str, dict[str, str]]] = None,
+    override_structure_overrides: Optional[dict[str, dict[str, list[str]]]] = None,
     reuse_from: Optional[str] = None,
 ) -> Path:
     """MVP-1.5b entry — single slide + composition planner v0 + 8 preset vocabulary.
@@ -4912,6 +5043,32 @@ def run_phase_z2_mvp1(
                         backend contract (KNOWN_AXES u1 + Vite allowlist u2 + typed
                         client u3 + stamper u4) end-to-end addressable from CLI without
                         diverging the function signature.
+      override_text_overrides : {zone_id: {text_path: value}} — IMP-56 (#90) u5
+                        axis. ``text_path`` = ``{slot_key}.{line_index}`` stamped
+                        by the u8 ``text_path_stamper`` (pending). Applied at
+                        Step 12 AFTER the AI-repair apply (IMP-47B u5) and
+                        BEFORE the ``step12_slot_payload.json`` artifact emit so
+                        the audit reflects user-edit final state. Per-zone
+                        tolerant — stale paths (frame swap / layout regression)
+                        skip silently. raw_content preserved (mutates
+                        ``zone['slot_payload']`` only ; ``debug_zones`` graph
+                        untouched). CLI / persistence fallback wiring is u16
+                        scope.
+      override_structure_overrides : {zone_id: {slot_order|hidden_slots: [slot_key,...]}}
+                        — IMP-56 (#90) u7 axis. SCOPE LOCKED to
+                        ``slot_order`` (partial reorder) + ``hidden_slots``
+                        (hide). Frame swap is rejected at the u6 validate
+                        gate (stays on the existing ``frames`` axis) so the
+                        Phase Z no-AI-HTML-structure invariant remains
+                        intact. Applied at Step 12 AFTER the u5
+                        text_overrides apply and BEFORE the
+                        ``step12_slot_payload.json`` artifact emit. Per-zone
+                        tolerant — stale slot_keys silently no-op (counted
+                        as ``skipped_zones``). raw_content preserved (only
+                        top-level slot_payload key membership + ordering
+                        mutated ; per-slot ``list[str]`` line content +
+                        ``debug_zones`` graph untouched). CLI / persistence
+                        fallback wiring is u16 scope.
       override_slide_css : Optional slide-level CSS string — IMP-45 (#74) u4 axis.
                         Marker-wrapped <style> block injected into ``final.html``
                         at Step 13 via :func:`src.slide_css_injector.inject_slide_css`
@@ -6607,6 +6764,59 @@ def run_phase_z2_mvp1(
         note="IMP-47B u6 — Step 12 AI repair gather + apply records per unit (route, skip_reason, apply_status, proposal). u7 coverage_invariant = pre/post AI source_section_ids set comparison.",
     )
 
+    # ─── Step 12 IMP-56 #90 u5 — Apply persisted text_overrides ───
+    # User text edits captured by the frontend (u12 capture path, pending)
+    # re-apply here so the next render shows them without re-clicking.
+    # Per-zone tolerant — stale ``text_path`` entries (frame swap / layout
+    # regression) skip silently. raw_content preserved : the helper only
+    # mutates ``zone["slot_payload"]`` ; ``debug_zones[i].source_section_ids``
+    # + ``MdxSection`` graph untouched. Audit artifact emits BEFORE the
+    # slot_payload artifact so reviewers see the post-override state.
+    text_overrides_audit = _apply_text_overrides_to_zones(
+        override_text_overrides or {}, zones_data,
+    )
+    _write_step_artifact(
+        run_dir, 12, "text_overrides",
+        data=text_overrides_audit,
+        step_status="done",
+        pipeline_path_connected=True,
+        inputs=["data/user_overrides/*.json"],
+        outputs=["step12_text_overrides.json"],
+        note=(
+            "IMP-56 #90 u5 — user text edit re-apply to slot_payload "
+            "(per-zone tolerant; raw_content preserved). text_path = "
+            "{slot_key}.{line_index} (u8 stamper contract)."
+        ),
+    )
+
+    # ─── Step 12 IMP-56 #90 u7 — Apply persisted structure_overrides ───
+    # User reorder / hide choices captured by the frontend (u13 capture
+    # path, pending) re-apply here. SCOPE LOCKED to slot_order +
+    # hidden_slots — frame swap rejected at u6 validate gate (stays on
+    # the existing `frames` axis) so the Phase Z no-AI-HTML-structure
+    # invariant remains intact. raw_content preserved : helper only
+    # reorders / removes top-level slot_payload keys ; per-slot line
+    # lists + ``debug_zones`` + ``MdxSection`` graph untouched. Audit
+    # artifact emits BEFORE the slot_payload artifact so reviewers see
+    # the post-override state.
+    structure_overrides_audit = _apply_structure_overrides_to_zones(
+        override_structure_overrides or {}, zones_data,
+    )
+    _write_step_artifact(
+        run_dir, 12, "structure_overrides",
+        data=structure_overrides_audit,
+        step_status="done",
+        pipeline_path_connected=True,
+        inputs=["data/user_overrides/*.json"],
+        outputs=["step12_structure_overrides.json"],
+        note=(
+            "IMP-56 #90 u7 — user reorder / hide re-apply to "
+            "slot_payload (SCOPE LOCKED to slot_order + hidden_slots ; "
+            "frame swap stays on the `frames` axis ; raw_content "
+            "preserved)."
+        ),
+    )
+
     # ─── Step 12: Slot Payload (actual values, mapper.py 결과) ───
     _write_step_artifact(
         run_dir, 12, "slot_payload",
@@ -8203,6 +8413,15 @@ if __name__ == "__main__":
             )
             sys.exit(2)
 
+    # IMP-56 (#90) u16 — text_overrides + structure_overrides are file-only
+    # axes (frontend captures via /api/user-overrides PUT; no CLI flag
+    # surface, by design — per-line text edits and per-zone slot reorders /
+    # hides are too granular for argparse). Initialize empty here so the
+    # user_overrides.json fallback below can fill them, mirroring the
+    # ``overrides_images`` (IMP-51 #79 u6) post-CLI / pre-_persisted shape.
+    overrides_text: dict[str, dict[str, str]] = {}
+    overrides_structure: dict[str, dict[str, list[str]]] = {}
+
     # IMP-52 (#80) u2 — user_overrides.json persistence fallback.
     # After argparse fully parses CLI flags, fill ONLY the axes the user
     # did NOT pass on the command line. CLI payload always wins over the
@@ -8309,6 +8528,51 @@ if __name__ == "__main__":
                         except (TypeError, ValueError):
                             continue
                 overrides_images = _accepted_img
+        # text_overrides — file-only (no CLI flag) → fill from file as
+        # dict[zone_id, dict[text_path, value]]. IMP-56 (#90) u16. Inline
+        # gate accepts only str-keyed inner dicts; the u4 validator runs
+        # again at Step 12 apply time, where malformed inner entries
+        # surface as silent per-zone skips in the ``step12_text_overrides``
+        # audit (Phase Z PZ-4 "no silent shrink" — count, don't drop).
+        if not overrides_text:
+            _file_text = _persisted.get("text_overrides")
+            if isinstance(_file_text, dict):
+                _accepted_text: dict[str, dict[str, str]] = {}
+                for _zid, _payload in _file_text.items():
+                    if isinstance(_zid, str) and isinstance(_payload, dict):
+                        _entries = {
+                            str(_k): str(_v)
+                            for _k, _v in _payload.items()
+                            if isinstance(_k, str) and isinstance(_v, str)
+                        }
+                        if _entries:
+                            _accepted_text[_zid] = _entries
+                overrides_text = _accepted_text
+        # structure_overrides — file-only → fill from file as dict[zone_id,
+        # {slot_order|hidden_slots: list[str]}]. IMP-56 (#90) u16. Inner
+        # keys locked to the two allowed names; the u6 validator drops any
+        # other key + frame-swap payloads at apply time so the CLI gate
+        # only does the list[str] structural coercion. Empty inner dicts
+        # are dropped here so ``overrides_structure or None`` collapses to
+        # ``None`` on the call site (matches IMP-51 #79 u6 ``or None`` shape).
+        if not overrides_structure:
+            _file_struct = _persisted.get("structure_overrides")
+            if isinstance(_file_struct, dict):
+                _accepted_struct: dict[str, dict[str, list[str]]] = {}
+                for _zid, _payload in _file_struct.items():
+                    if isinstance(_zid, str) and isinstance(_payload, dict):
+                        _entries_s: dict[str, list[str]] = {}
+                        for _k, _v in _payload.items():
+                            if (
+                                _k in ("slot_order", "hidden_slots")
+                                and isinstance(_v, list)
+                            ):
+                                _entries_s[_k] = [
+                                    s for s in _v if isinstance(s, str)
+                                ]
+                        if _entries_s:
+                            _accepted_struct[_zid] = _entries_s
+                overrides_structure = _accepted_struct
 
     # IMP-43 (#72) u1 — fail-closed reuse_from precondition guard.
     # Placed AFTER the user_overrides.json merge so persisted overrides
@@ -8350,5 +8614,7 @@ if __name__ == "__main__":
         override_section_assignments=overrides_section_assignments or None,
         override_image_overrides=overrides_images or None,
         override_slide_css=_final_override_slide_css,
+        override_text_overrides=overrides_text or None,
+        override_structure_overrides=overrides_structure or None,
         reuse_from=args.reuse_from,
     )

src/structure_override_resolver.py

@@ -0,0 +1,189 @@
+"""IMP-56 (#90) u6 — structure_override resolver (validator + apply).
+
+Step-22 user structure-edit persist axis. Consumed by Step 12 (u7 wiring)
+so a prior render's reorder / hide choices re-apply to the next render
+without re-clicking.
+
+Schema (defined verbatim in ``src/user_overrides_io.py:30`` u2) ::
+
+    structure_overrides = {
+        <zone_id>: {
+            "slot_order":   [<slot_key>, ...],   # optional, partial reorder
+            "hidden_slots": [<slot_key>, ...],   # optional, hide these slot_keys
+        },
+        ...
+    }
+
+SCOPE LOCK (Stage 2 u6 contract, IMP-56 #90 u2 docstring) :
+
+    The only allowed inner keys are ``slot_order`` and ``hidden_slots``.
+    Any other key (e.g., ``frame_id``, ``template_id``, ``unit_id``,
+    ``slot_payload``) is treated as a frame-swap / DOM-rebuild attempt and
+    is DROPPED at validate time. Frame swap stays on the existing
+    ``frames`` axis so the Phase Z no-AI-HTML-structure invariant remains
+    intact. There is intentionally NO escape hatch through this axis.
+
+API (deterministic, no AI) :
+
+- ``validate_structure_overrides(overrides)`` → sanitized copy. Per-entry
+  tolerant (drops malformed rows; never rejects the whole batch — mirrors
+  ``src.text_override_resolver.validate_text_overrides`` u4 contract).
+- ``apply_structure_override(zone, override)`` → ``True`` if the slot-payload
+  mapping was mutated (any hide or any reorder), ``False`` otherwise. The
+  ``zone`` argument is the slot-payload mapping at Step 12 (a mutable
+  mapping whose keys are slot_keys and whose values are typically
+  ``list[str]`` of lines). Identity-preserving: mutates in-place via
+  ``clear`` + ``update`` so caller references remain valid.
+
+Guardrails (refs : Stage 1 binding contract, Stage 2 unit u6) :
+
+- raw_content preservation is a wiring-layer (u7) responsibility — the
+  resolver only ever reorders / removes top-level slot_payload entries.
+  Per-slot ``list[str]`` line content is never inspected or mutated here.
+- AI-isolation : pure deterministic Python; no LLM calls.
+- Carve-out (IMP-46 #62) : brand-new module, does not touch the #76
+  commit ``1186ad8`` cache region.
+"""
+from __future__ import annotations
+
+from typing import Any, Mapping, MutableMapping
+
+
+class InvalidStructureOverride(ValueError):
+    """Reserved for future strict-mode parse errors.
+
+    Currently unused — the resolver follows the u4 per-entry-tolerant
+    contract and silently drops malformed rows at validate time rather
+    than raising. Kept as a public surface so u7 wiring (and future
+    strict-mode callers) can distinguish source-malformation from
+    stale-DOM misses without an API rev.
+    """
+
+
+_ALLOWED_INNER_KEYS: frozenset[str] = frozenset({"slot_order", "hidden_slots"})
+
+
+def _sanitize_slot_list(raw: Any) -> list[str]:
+    """Return a fresh list of non-empty string slot_keys (drop the rest)."""
+    if not isinstance(raw, list):
+        return []
+    out: list[str] = []
+    seen: set[str] = set()
+    for slot in raw:
+        if not isinstance(slot, str) or not slot:
+            continue
+        if slot in seen:
+            # De-dup defensively — a duplicate slot_key in slot_order would
+            # be meaningless (dicts can hold each key once); duplicate in
+            # hidden_slots is redundant. Drop subsequent occurrences.
+            continue
+        seen.add(slot)
+        out.append(slot)
+    return out
+
+
+def validate_structure_overrides(
+    overrides: Any,
+) -> dict[str, dict[str, list[str]]]:
+    """Return a sanitized copy of ``overrides`` (per-entry tolerant).
+
+    Drops:
+      - non-string or empty zone_ids,
+      - non-mapping per-zone payloads,
+      - per-zone inner keys other than ``slot_order`` / ``hidden_slots``
+        (frame-swap attempts are dropped at this gate — see SCOPE LOCK),
+      - non-list ``slot_order`` / ``hidden_slots`` values,
+      - non-string or empty slot_key entries within those lists,
+      - per-zone payloads that contain neither a non-empty ``slot_order``
+        nor a non-empty ``hidden_slots`` after sanitization (empty intent
+        carries no signal).
+
+    Returns a fresh ``dict`` AND fresh nested dicts / lists so callers can
+    use the result as a working buffer without aliasing the persisted
+    payload from ``user_overrides_io.load``.
+    """
+    if not isinstance(overrides, Mapping):
+        return {}
+    out: dict[str, dict[str, list[str]]] = {}
+    for zone_id, mapping in overrides.items():
+        if not isinstance(zone_id, str) or not zone_id:
+            continue
+        if not isinstance(mapping, Mapping):
+            continue
+        zone_out: dict[str, list[str]] = {}
+        for inner_key, inner_value in mapping.items():
+            if inner_key not in _ALLOWED_INNER_KEYS:
+                # Frame-swap attempt or unknown key — drop silently per
+                # SCOPE LOCK. No mechanism through this axis.
+                continue
+            sanitized = _sanitize_slot_list(inner_value)
+            if sanitized:
+                zone_out[inner_key] = sanitized
+        if zone_out:
+            out[zone_id] = zone_out
+    return out
+
+
+def apply_structure_override(
+    zone: MutableMapping[str, Any],
+    override: Mapping[str, Any],
+) -> bool:
+    """Apply ONE structure override to ``zone`` in-place.
+
+    ``zone`` is the slot-payload mapping at Step 12 — i.e. a mutable
+    mapping whose keys are slot_keys and whose values are the per-slot
+    line lists (or other content payload). Mutation is restricted to
+    top-level key membership + ordering; per-slot values are NEVER
+    inspected or modified here.
+
+    ``override`` is the per-zone payload after :func:`validate_structure_overrides`
+    sanitization — i.e. a mapping with only ``slot_order`` and / or
+    ``hidden_slots`` keys, each holding a list of non-empty str slot_keys.
+    This function is also defensive: if non-list values leak through, they
+    are treated as empty (no raise).
+
+    Semantics :
+      1. ``hidden_slots`` are popped first. Entries absent from ``zone``
+         are silently skipped (stale slot_keys from a prior frame).
+      2. ``slot_order`` partially reorders the surviving slot_keys:
+         listed keys (that are present in ``zone``) move to the front in
+         the given order; remaining keys keep their original relative
+         order at the tail. Unknown slot_keys are silently skipped.
+
+    Returns ``True`` if the zone's slot-payload mapping was mutated (any
+    hide that removed a key OR any reorder that changed key order),
+    ``False`` otherwise. Identity-preserving: rebuilds via
+    ``clear`` + ``update`` so the caller's reference to ``zone`` remains
+    valid.
+    """
+    mutated = False
+
+    raw_hidden = override.get("hidden_slots") if isinstance(override, Mapping) else None
+    hidden = _sanitize_slot_list(raw_hidden)
+    for slot in hidden:
+        if slot in zone:
+            del zone[slot]
+            mutated = True
+
+    raw_order = override.get("slot_order") if isinstance(override, Mapping) else None
+    desired_order_seed = _sanitize_slot_list(raw_order)
+
+    current_order = list(zone.keys())
+    desired_order: list[str] = []
+    seen: set[str] = set()
+    for slot in desired_order_seed:
+        if slot in zone and slot not in seen:
+            desired_order.append(slot)
+            seen.add(slot)
+    for slot in current_order:
+        if slot not in seen:
+            desired_order.append(slot)
+            seen.add(slot)
+
+    if desired_order != current_order:
+        snapshot = {k: zone[k] for k in desired_order}
+        zone.clear()
+        zone.update(snapshot)
+        mutated = True
+
+    return mutated

src/text_override_resolver.py

@@ -0,0 +1,143 @@
+"""IMP-56 (#90) u4 — text_override resolver (validator + apply).
+
+Step-22 user text-edit persist axis. Consumed by Step 12 (u5 wiring) so a
+prior render's text edits re-apply to the next render without re-clicking.
+
+Schema (defined verbatim in ``src/user_overrides_io.py:29`` u1) ::
+
+    text_overrides = {
+        <zone_id>: {<text_path>: <value: str>},
+        ...
+    }
+
+``text_path`` is the ``{slot_key}.{line_index}`` stamp emitted at Step 13
+by the u8 ``text_path_stamper`` (pending unit) and surfaced to the frontend
+SlideCanvas (u12) as ``data-text-path`` attributes on editable text nodes.
+The ``{slot_key}`` is a frame contract slot identifier (e.g.,
+``slot_title``); the ``{line_index}`` is the 0-based ordinal of the line
+within that slot's rendered text (typically one bullet / one paragraph).
+
+API (deterministic, no AI) :
+
+- ``parse_text_path(text_path)`` → ``(slot_key, line_index)`` or raises.
+- ``validate_text_overrides(overrides)`` → sanitized copy (drops malformed
+  per-entry; never rejects the whole batch — mirrors the per-entry
+  tolerance contract of ``src.image_id_stamper.build_image_overrides_style``
+  IMP-51 #79 u7).
+- ``apply_text_override(zone, text_path, value)`` → ``True`` on in-place
+  mutation; ``False`` if the path is absent / out-of-range. The ``zone``
+  argument is the slot-lines mapping at Step 12 — i.e. a mutable mapping
+  where ``zone[slot_key]`` is a ``list[str]`` of line strings. Wiring at
+  Step 12 (u5) is responsible for extracting that mapping from whatever
+  composition object holds it; this resolver is decoupled from the wrapper
+  shape so it can be re-targeted at Stage 5 (Step 12) layer-A or layer-B
+  composition data without an API rev.
+
+Guardrails (refs : Stage 1 binding contract, Stage 2 unit u4) :
+
+- raw_content preservation is a wiring-layer (u5) responsibility — the
+  resolver itself only ever mutates the lines mapping it was handed.
+- AI-isolation : pure deterministic Python; no LLM calls.
+- Carve-out (IMP-46 #62) : brand-new module, does not touch the #76
+  commit ``1186ad8`` cache region.
+"""
+from __future__ import annotations
+
+from typing import Any, Mapping, MutableMapping
+
+
+class InvalidTextOverride(ValueError):
+    """Raised when a ``text_path`` is malformed (parse-time)."""
+
+
+def parse_text_path(text_path: str) -> tuple[str, int]:
+    """Parse ``{slot_key}.{line_index}`` into ``(slot_key, line_index)``.
+
+    ``slot_key`` may itself contain ``.`` (e.g., compound keys), so the
+    parse splits on the LAST ``.`` only — ``rpartition`` semantics.
+    """
+    if not isinstance(text_path, str) or not text_path:
+        raise InvalidTextOverride(
+            f"text_path must be a non-empty string, got: {text_path!r}"
+        )
+    if "." not in text_path:
+        raise InvalidTextOverride(
+            f"text_path must contain '.' separator, got: {text_path!r}"
+        )
+    slot_key, _, idx_str = text_path.rpartition(".")
+    if not slot_key or not idx_str:
+        raise InvalidTextOverride(
+            f"text_path slot_key and line_index must both be non-empty, "
+            f"got: {text_path!r}"
+        )
+    try:
+        idx = int(idx_str)
+    except ValueError as exc:
+        raise InvalidTextOverride(
+            f"text_path line_index must be int, got: {text_path!r}"
+        ) from exc
+    if idx < 0:
+        raise InvalidTextOverride(
+            f"text_path line_index must be >= 0, got: {idx} in {text_path!r}"
+        )
+    return slot_key, idx
+
+
+def validate_text_overrides(overrides: Any) -> dict[str, dict[str, str]]:
+    """Return a sanitized copy of ``overrides`` (per-entry tolerant).
+
+    Drops:
+      - non-string or empty zone_ids,
+      - non-mapping per-zone payloads,
+      - non-string text_path keys, non-string values,
+      - text_paths that fail :func:`parse_text_path`.
+
+    Returns a fresh ``dict`` so callers can mutate without aliasing the
+    persisted payload from ``user_overrides_io.load``.
+    """
+    if not isinstance(overrides, Mapping):
+        return {}
+    out: dict[str, dict[str, str]] = {}
+    for zone_id, mapping in overrides.items():
+        if not isinstance(zone_id, str) or not zone_id:
+            continue
+        if not isinstance(mapping, Mapping):
+            continue
+        zone_out: dict[str, str] = {}
+        for text_path, value in mapping.items():
+            if not isinstance(text_path, str) or not isinstance(value, str):
+                continue
+            try:
+                parse_text_path(text_path)
+            except InvalidTextOverride:
+                continue
+            zone_out[text_path] = value
+        if zone_out:
+            out[zone_id] = zone_out
+    return out
+
+
+def apply_text_override(
+    zone: MutableMapping[str, Any],
+    text_path: str,
+    value: str,
+) -> bool:
+    """Apply ONE text override to ``zone`` in-place.
+
+    ``zone`` is the slot-lines mapping at Step 12 — i.e. a mutable mapping
+    where ``zone[slot_key]`` is a ``list[str]`` of line strings.
+
+    Returns ``True`` when the value was replaced. Returns ``False`` (no
+    mutation) when the ``slot_key`` is absent, the slot is not a list, or
+    ``line_index`` is out of range. Out-of-range / absent paths are NOT an
+    error — they happen naturally when a prior render's overrides target a
+    slot the new render no longer emits (frame swap, layout regression).
+    """
+    slot_key, idx = parse_text_path(text_path)
+    if slot_key not in zone:
+        return False
+    lines = zone[slot_key]
+    if not isinstance(lines, list) or idx >= len(lines):
+        return False
+    lines[idx] = value
+    return True

src/text_path_stamper.py

@@ -0,0 +1,155 @@
+"""IMP-56 (#90) u8 — text_path stamper for Phase Z final.html.
+
+Annotates rendered ``text-line`` DOM elements with a stable
+``data-text-path="{slot_key}.{line_index}"`` attribute so the frontend
+SlideCanvas (u10~u12) can attribute per-line edits back to the
+``text_overrides`` axis (u1 schema, u4 resolver, u5 Step-12 apply).
+
+DOM contract (single point of truth — mirrored verbatim across the axis) ::
+
+    .text-line[data-text-path="{slot_key}.{line_index}"]
+
+The ``{slot_key}.{line_index}`` grammar matches
+:func:`src.text_override_resolver.parse_text_path` verbatim (split on LAST
+``.`` — compound slot keys with embedded dots are supported).
+
+The text-line element format is emitted by every Phase Z family / frame
+template (e.g. ``templates/phase_z2/families/bim_current_problems_paired.html``
+line 143)::
+
+    <div class="text-line[ ...modifier classes...]">{{ line.text | safe }}</div>
+
+The stamper finds each ``text-line`` opening tag with a permissive regex
+and injects ``data-text-path="..."`` as the FIRST attribute. Existing
+attributes (class, etc.) are preserved verbatim. The injection is
+idempotent — a previously stamped element is left alone.
+
+Stamping order : the stamper iterates ``slot_payload`` in dict-iteration
+order and yields one stamp per ``list`` entry. The DOM walk consumes
+stamps in left-to-right order; templates currently emit slot lines in
+the same order they appear in ``slot_payload`` so the alignment holds.
+If a future template diverges, u9 wiring can pre-build the desired
+``(slot_key, line_index)`` sequence and pass it explicitly through the
+``stamps`` arg of :func:`stamp_zone_html`.
+
+Forward-compat / safety :
+- Scalar (non-list) slot values are silently skipped — they render
+  outside ``text-line`` divs (frame title, pill labels, etc.) and are
+  not addressable via the line-index grammar.
+- Excess ``text-line`` elements beyond ``sum(len(v) for v in
+  slot_payload.values() if isinstance(v, list))`` are left unstamped.
+- Re-stamping (idempotent) preserves the first stamp.
+
+Guardrails (refs : Stage 1 binding contract, Stage 2 unit u8) :
+- AI-isolation : pure deterministic Python; no LLM calls.
+- Carve-out (IMP-46 #62) : brand-new module; does not touch the #76
+  commit ``1186ad8`` cache region.
+- Idempotent : ``data-text-path`` probe short-circuits before re-inject.
+- u9 wiring (separate unit) is the only consumer; this module emits no
+  artifacts and reads no global state.
+"""
+from __future__ import annotations
+
+import re
+from typing import Any, Iterable, Iterator, Mapping
+
+TEXT_PATH_ATTR: str = "data-text-path"
+
+# Matches a ``<div ... class="... text-line ..." ...>`` opening tag.
+# Group 1 captures the inner attribute string verbatim (incl. leading
+# whitespace) so the rewriter can re-emit it unchanged after injection.
+_TEXT_LINE_TAG_RE = re.compile(
+    r'<div\b((?=[^>]*\bclass\s*=\s*"[^"]*\btext-line\b)[^>]*?)>',
+    flags=re.IGNORECASE | re.DOTALL,
+)
+# Probe for an existing ``data-text-path`` attribute (any value, any
+# quote) so re-stamping is idempotent.
+_HAS_TEXT_PATH_RE = re.compile(r"""\bdata-text-path\s*=""", flags=re.IGNORECASE)
+
+
+def build_text_path(slot_key: str, line_index: int) -> str:
+    """Return the canonical ``{slot_key}.{line_index}`` text_path string.
+
+    Mirrors the inverse of :func:`src.text_override_resolver.parse_text_path`
+    (last-dot split). ``slot_key`` may itself contain ``.`` (compound keys).
+    """
+    if not isinstance(slot_key, str) or not slot_key:
+        raise ValueError(
+            f"slot_key must be a non-empty string, got: {slot_key!r}"
+        )
+    if isinstance(line_index, bool) or not isinstance(line_index, int):
+        raise ValueError(
+            f"line_index must be a non-negative int, got: {line_index!r}"
+        )
+    if line_index < 0:
+        raise ValueError(
+            f"line_index must be a non-negative int, got: {line_index!r}"
+        )
+    return f"{slot_key}.{line_index}"
+
+
+def iter_zone_stamps(
+    slot_payload: Mapping[str, Any],
+) -> Iterator[tuple[str, int]]:
+    """Yield ``(slot_key, line_index)`` for every list-valued slot line.
+
+    Iteration order matches ``slot_payload`` dict iteration order. Non-
+    string / empty slot_keys are skipped. Non-list values are skipped
+    (scalar slots render outside ``text-line`` divs).
+    """
+    if not isinstance(slot_payload, Mapping):
+        return
+    for slot_key, value in slot_payload.items():
+        if not isinstance(slot_key, str) or not slot_key:
+            continue
+        if not isinstance(value, list):
+            continue
+        for line_index in range(len(value)):
+            yield slot_key, line_index
+
+
+def stamp_zone_html(
+    zone_html: str,
+    slot_payload_or_stamps: Mapping[str, Any] | Iterable[tuple[str, int]],
+) -> str:
+    """Stamp ``text-line`` opening tags in ``zone_html`` with ``data-text-path``.
+
+    The second arg accepts either:
+      - a ``slot_payload`` ``Mapping`` (uses :func:`iter_zone_stamps` order), or
+      - an iterable of pre-built ``(slot_key, line_index)`` tuples.
+
+    Stamps are consumed in left-to-right DOM order. A text-line already
+    carrying ``data-text-path`` is left unchanged (idempotent). Excess
+    text-line elements beyond the stamp sequence are also left unchanged.
+
+    Returns ``zone_html`` unchanged when there are no stamps to apply or
+    the input is not a non-empty string.
+    """
+    if not isinstance(zone_html, str) or not zone_html:
+        return zone_html
+    if isinstance(slot_payload_or_stamps, Mapping):
+        stamps = list(iter_zone_stamps(slot_payload_or_stamps))
+    else:
+        stamps = [
+            (sk, li)
+            for (sk, li) in slot_payload_or_stamps
+            if isinstance(sk, str) and sk and isinstance(li, int)
+            and not isinstance(li, bool) and li >= 0
+        ]
+    if not stamps:
+        return zone_html
+    counter = {"i": 0}
+
+    def _replace(match: re.Match[str]) -> str:
+        attrs = match.group(1) or ""
+        if _HAS_TEXT_PATH_RE.search(attrs):
+            return match.group(0)
+        i = counter["i"]
+        if i >= len(stamps):
+            return match.group(0)
+        counter["i"] = i + 1
+        slot_key, line_index = stamps[i]
+        path = build_text_path(slot_key, line_index)
+        return f'<div {TEXT_PATH_ATTR}="{path}"{attrs}>'
+
+    return _TEXT_LINE_TAG_RE.sub(_replace, zone_html)

src/user_overrides_io.py

@@ -5,10 +5,18 @@ auto-restores user choices without re-clicking. Source of truth = MDX-keyed
 file (stem of the MDX path), NOT ``data/runs/<run_id>/`` which mints a fresh
 run_id per ``/api/run`` invocation.
 
-Schema (7 axes; stable order; IMP-51 #79 u1 added ``image_overrides``;
+Schema (9 axes; stable order; IMP-51 #79 u1 added ``image_overrides``;
 IMP-45 #74 u1 added ``slide_css``; IMP-55 #93 u1 added
 ``manual_section_assignment`` as a bool intent marker so the backend can
-distinguish a user drag-drop from frontend auto-carry zone_sections):
+distinguish a user drag-drop from frontend auto-carry zone_sections;
+IMP-56 #90 u1 added ``text_overrides`` as a Step-22 text-edit persist axis
+keyed by ``{zone_id: {text_path: value}}`` where ``text_path`` is the
+``{slot_key}.{line_index}`` stamp emitted by u8; IMP-56 #90 u2 added
+``structure_overrides`` as a Step-22 structure-edit persist axis keyed by
+``{zone_id: {"slot_order": [<slot_key>, ...], "hidden_slots": [<slot_key>, ...]}}``
+— scope is intentionally LOCKED to slot reorder + hide; frame swap stays
+on the existing ``frames`` axis to prevent the Phase Z regression of
+AI-driven HTML structure mutation):
 
     {
       "layout":                    <string|null>,
@@ -17,7 +25,9 @@ distinguish a user drag-drop from frontend auto-carry zone_sections):
       "frames":                    {<unit_id>: <template_id>},
       "image_overrides":           {<image_id>: {"x": float, "y": float, "w": float, "h": float}},
       "slide_css":                 <string|null>,
-      "manual_section_assignment": <bool>
+      "manual_section_assignment": <bool>,
+      "text_overrides":            {<zone_id>: {<text_path>: <string>}},
+      "structure_overrides":       {<zone_id>: {"slot_order": [<slot_key>, ...], "hidden_slots": [<slot_key>, ...]}}
     }
 
 ``image_id`` is the stable identifier emitted by the user-content image
@@ -58,13 +68,21 @@ from typing import Any, Optional
 _PKG_ROOT = Path(__file__).resolve().parent.parent
 DEFAULT_OVERRIDES_ROOT = _PKG_ROOT / "data" / "user_overrides"
 
-# The seven in-scope axes (IMP-51 #79 u1 added ``image_overrides``; IMP-45
+# The nine in-scope axes (IMP-51 #79 u1 added ``image_overrides``; IMP-45
 # #74 u1 added ``slide_css``; IMP-55 #93 u1 added
 # ``manual_section_assignment`` — bool intent marker that gates whether
-# persisted ``zone_sections`` are consumed by the backend pipeline). Any
-# other top-level key in the file is preserved but ignored by callers —
-# keeps the file forward-compatible with future axes (e.g., zone_sizes)
-# without a schema bump here.
+# persisted ``zone_sections`` are consumed by the backend pipeline; IMP-56
+# #90 u1 added ``text_overrides`` — Step-22 text-edit persist axis keyed by
+# ``{zone_id: {text_path: value}}`` where ``text_path`` is the
+# ``{slot_key}.{line_index}`` stamp emitted by u8 / consumed by u4+u5;
+# IMP-56 #90 u2 added ``structure_overrides`` — Step-22 structure-edit
+# persist axis keyed by ``{zone_id: {"slot_order": [...], "hidden_slots":
+# [...]}}``, scope LOCKED to slot reorder + hide so the resolver (u6) /
+# Step-12 apply (u7) cannot mutate frame identity — frame swap stays on
+# the existing ``frames`` axis to keep Phase Z's no-AI-HTML-structure
+# invariant intact). Any other top-level key in the file is preserved but
+# ignored by callers — keeps the file forward-compatible with future axes
+# (e.g., zone_sizes) without a schema bump here.
 KNOWN_AXES: tuple[str, ...] = (
     "layout",
     "zone_geometries",
@@ -73,6 +91,8 @@ KNOWN_AXES: tuple[str, ...] = (
     "image_overrides",
     "slide_css",
     "manual_section_assignment",
+    "text_overrides",
+    "structure_overrides",
 )
 
 # Key validation — MDX stem must be safe for filesystem use. Allow

templates/phase_z2/slide_base.html

@@ -355,6 +355,38 @@
       line-height: 1.5;
       color: #1e293b;
     }
+
+    /* ── IMP-90 u17 : print mode (Step 22 user-edit + Export).
+         Companion JS at body end opens popups so FULL raw_content prints. */
+    @media print {
+      @page { size: 1280px 720px; margin: 0; }
+      html, body {
+        background: #fff !important;
+        padding: 0 !important;
+        margin: 0 !important;
+        min-height: 0 !important;
+        display: block !important;
+      }
+      .slide {
+        box-shadow: none !important;
+        page-break-inside: avoid;
+        break-inside: avoid;
+      }
+      .zone__popup-summary { display: none !important; }
+      .zone__popup-details,
+      .zone__popup-details[open] { position: static !important; }
+      .zone__popup-body {
+        position: static !important;
+        top: auto !important;
+        right: auto !important;
+        max-height: none !important;
+        overflow: visible !important;
+        box-shadow: none !important;
+        border: none !important;
+        width: auto !important;
+        padding: 6px 0 0 0 !important;
+      }
+    }
   </style>
 </head>
 <body>
@@ -389,5 +421,22 @@
     </div>
     {% endif %}
   </div>
+  <script>
+  // IMP-90 u17 — beforeprint popup auto-expand (CLAUDE.md 자세히보기 contract).
+  // Body-level handler (outside any per-zone popup block) so the popup-render
+  // JS-free invariant (IMP-35 u8) is preserved on the per-zone path.
+  window.addEventListener('beforeprint', function () {
+    document.querySelectorAll('details').forEach(function (d) {
+      d.dataset.imp90PrintRestore = d.open ? '1' : '0';
+      d.open = true;
+    });
+  });
+  window.addEventListener('afterprint', function () {
+    document.querySelectorAll('details').forEach(function (d) {
+      if (d.dataset.imp90PrintRestore === '0') d.open = false;
+      delete d.dataset.imp90PrintRestore;
+    });
+  });
+  </script>
 </body>
 </html>

tests/phase_z2/test_slide_base_print_mode.py

@@ -0,0 +1,151 @@
+"""IMP-90 (#90) u17 — slide_base.html print-mode contract tests.
+
+Stage 2 plan contract (unit u17):
+  Step 22 user-edit + Export track. The Phase Z2 print path MUST
+  auto-expand <details> popups so the FULL raw_content (MDX 원문 무손실
+  보존) is included when the user prints / exports from the browser.
+
+  u17 introduces two coordinated surfaces in
+  ``templates/phase_z2/slide_base.html``:
+
+    1. ``@media print`` CSS block — neutralizes the on-screen-only body
+       centering / box-shadow / 280px popup card clipping so the slide
+       prints at 1280×720 with the expanded popup body in static flow.
+
+    2. ``beforeprint`` / ``afterprint`` JavaScript hook at body level —
+       toggles ``details.open`` to ``true`` before the print snapshot
+       and restores the user's prior open/closed state afterwards. Body
+       level (outside any ``<details>...</details>`` block) preserves
+       the IMP-35 u8 popup-render JS-free invariant
+       (tests/phase_z2/test_slide_base_popup_render.py
+       ``test_popup_emits_no_javascript_on_render_path``).
+
+Invariants locked here:
+  P-1: ``@media print`` block is emitted exactly once in the render.
+  P-2: ``@page`` size matches the 1280×720 slide canvas.
+  P-3: ``.slide`` box-shadow + body padding/min-height neutralized at
+       print time.
+  P-4: ``.zone__popup-summary`` hidden, popup body switches from
+       absolute to static flow with unconstrained height — the popup
+       card chrome (border / shadow / 280px max-height) is unset.
+  P-5: ``beforeprint`` + ``afterprint`` listeners are wired at body
+       level (NOT inside the per-zone details block) so the popup
+       render path stays JS-free.
+  P-6: Restore semantics — the script preserves the user's prior
+       open/closed state via a single ``dataset.imp90PrintRestore`` key
+       (no global state, no event-bus mutation).
+"""
+from __future__ import annotations
+
+import re
+
+from src.phase_z2_pipeline import render_slide
+
+
+def _layout_css() -> dict:
+    return {"areas": '"primary"', "cols": "1fr", "rows": "1fr"}
+
+
+def _zone(**overrides) -> dict:
+    base = {
+        "position": "primary",
+        "template_id": "__empty__",
+        "slot_payload": {},
+    }
+    base.update(overrides)
+    return base
+
+
+def _render() -> str:
+    return render_slide(
+        slide_title="t",
+        slide_footer=None,
+        zones_data=[_zone()],
+        layout_preset="single",
+        layout_css=_layout_css(),
+        gap_px=14,
+    )
+
+
+# ─── P-1 ─ media print block presence ───────────────────────────────
+
+
+def test_media_print_block_emitted_once():
+    html = _render()
+    matches = re.findall(r"@media\s+print\s*\{", html)
+    assert len(matches) == 1
+
+
+# ─── P-2 ─ @page size matches slide canvas ──────────────────────────
+
+
+def test_page_size_matches_slide_canvas():
+    html = _render()
+    flat = re.sub(r"\s+", " ", html)
+    assert "@page { size: 1280px 720px; margin: 0; }" in flat
+
+
+# ─── P-3 ─ standalone chrome neutralized at print ───────────────────
+
+
+def test_slide_box_shadow_neutralized_at_print():
+    html = _render()
+    flat = re.sub(r"\s+", " ", html)
+    print_block = re.search(r"@media\s+print\s*\{(.*?)\}\s*</style>", flat)
+    assert print_block is not None
+    body = print_block.group(1)
+    assert "box-shadow: none !important" in body
+    assert "padding: 0 !important" in body
+    assert "min-height: 0 !important" in body
+
+
+# ─── P-4 ─ popup body switches to static flow, summary hidden ───────
+
+
+def test_popup_card_chrome_unset_at_print():
+    html = _render()
+    flat = re.sub(r"\s+", " ", html)
+    print_block = re.search(r"@media\s+print\s*\{(.*?)\}\s*</style>", flat)
+    assert print_block is not None
+    body = print_block.group(1)
+    assert ".zone__popup-summary { display: none !important; }" in body
+    assert "position: static !important" in body
+    assert "max-height: none !important" in body
+    assert "overflow: visible !important" in body
+
+
+# ─── P-5 ─ beforeprint hook is body-level (NOT inside <details>) ────
+
+
+def test_beforeprint_and_afterprint_listeners_present():
+    html = _render()
+    assert "addEventListener('beforeprint'" in html
+    assert "addEventListener('afterprint'" in html
+
+
+def test_print_script_is_outside_any_details_block():
+    """The IMP-35 u8 popup render path is JS-free. Our print script
+    sits at body level after the slide div, so no <script> appears
+    inside a <details>...</details> popup block."""
+    html = _render(
+    )
+    # No <details> in the no-popup baseline — but the assertion still
+    # holds defensively: locate every <details>...</details> block (if
+    # any) and confirm no <script> tag appears inside.
+    for block in re.findall(r"<details[\s>].*?</details>", html, re.DOTALL):
+        assert "<script" not in block
+        assert "addEventListener" not in block
+
+
+# ─── P-6 ─ restore semantics ────────────────────────────────────────
+
+
+def test_restore_uses_single_dataset_key():
+    """Restore strategy uses one dataset key
+    (``dataset.imp90PrintRestore``) — no global Set/Map, no mutation
+    of any other DOM attribute. Locks the minimal-surface contract."""
+    html = _render()
+    assert "imp90PrintRestore" in html
+    # Restore branch only sets open=false when the prior state was '0'.
+    assert "imp90PrintRestore === '0'" in html
+    assert "d.open = true" in html

tests/test_phase_z2_structure_overrides.py

@@ -0,0 +1,216 @@
+"""IMP-56 (#90) u7 — Step 12 ``structure_overrides`` apply unit tests.
+
+Synthetic — exercises ``_apply_structure_overrides_to_zones`` directly
+without running the full Phase Z 22-step pipeline. The helper is
+decoupled from ``MdxSection`` / ``CompositionUnit`` graphs and only
+consumes a minimal ``[{position, slot_payload}, ...]`` zone list, so a
+synthetic fixture is sufficient to lock the contract.
+
+Coverage axes (Stage 2 plan u7 + Stage 1 binding contract) :
+
+  - reorder happy path : ``slot_order`` partial reorder mutates
+    ``zone['slot_payload']`` key order in place (caller reference stays
+    valid via clear+update rebuild contract documented at u6).
+  - hide happy path : ``hidden_slots`` pops the listed keys.
+  - stale slot_key : absent slot_keys silently no-op (count toward
+    ``skipped_zones`` if the whole override produces no mutation).
+  - SCOPE LOCK : frame-swap-shaped inner keys (``frame_id``,
+    ``template_id``) are dropped by the u6 validate gate and therefore
+    never reach the apply path here.
+  - raw_content preservation : per-slot ``list[str]`` line content
+    untouched; out-of-band sentinels (mirror of ``debug_zones`` graph)
+    stay byte-identical.
+  - audit shape : ``applied_zones`` / ``skipped_zones`` / ``per_zone``
+    keys present and counts consistent with the input batch.
+  - empty / ``None`` batch is a no-op (empty audit).
+
+Fully synthetic per Codex generalization guardrail (MOCK_ prefix).
+NO real catalog template_id / frame_id, NO ``v4_full32_result.yaml``
+dependency.
+"""
+from __future__ import annotations
+
+import pytest
+
+from src.phase_z2_pipeline import _apply_structure_overrides_to_zones
+
+
+# ─── Synthetic fixture helpers ──────────────────────────────────────
+
+
+def _zone(position: str, slot_payload: dict) -> dict:
+    """Minimal zone dict mirroring the Step 12 ``zones_data[i]`` shape."""
+    return {
+        "position": position,
+        "template_id": "MOCK_T_phase_z2_structure_overrides",
+        "slot_payload": slot_payload,
+        "content_weight": 1.0,
+        "min_height_px": 200,
+    }
+
+
+# ─── Case 1 : reorder happy path ──────────────────────────────────────
+
+
+def test_apply_reorders_slot_payload_keys_in_place():
+    payload = {"slot_a": ["A"], "slot_b": ["B"], "slot_c": ["C"]}
+    zones = [_zone("top", payload)]
+    overrides = {"top": {"slot_order": ["slot_c", "slot_a"]}}
+
+    audit = _apply_structure_overrides_to_zones(overrides, zones)
+
+    # Caller reference (payload) stays valid via clear+update rebuild.
+    assert zones[0]["slot_payload"] is payload
+    assert list(payload.keys()) == ["slot_c", "slot_a", "slot_b"]
+    # Per-slot list[str] content untouched (raw_content invariant).
+    assert payload["slot_a"] == ["A"]
+    assert payload["slot_b"] == ["B"]
+    assert payload["slot_c"] == ["C"]
+    assert audit["applied_zones"] == 1
+    assert audit["skipped_zones"] == 0
+    assert audit["per_zone"] == [{"position": "top", "mutated": True}]
+
+
+# ─── Case 2 : hide happy path ─────────────────────────────────────────
+
+
+def test_apply_hides_listed_slot_keys():
+    payload = {"slot_a": ["A"], "slot_b": ["B"], "slot_c": ["C"]}
+    zones = [_zone("top", payload)]
+    overrides = {"top": {"hidden_slots": ["slot_b"]}}
+
+    audit = _apply_structure_overrides_to_zones(overrides, zones)
+
+    assert "slot_b" not in payload
+    assert list(payload.keys()) == ["slot_a", "slot_c"]
+    assert audit["applied_zones"] == 1
+    assert audit["per_zone"] == [{"position": "top", "mutated": True}]
+
+
+# ─── Case 3 : stale slot_key — frame swap / layout regression ─────────
+
+
+def test_stale_slot_key_silently_no_op():
+    """Absent slot_keys produce no mutation; the zone counts toward skipped_zones."""
+    payload = {"slot_a": ["A"]}
+    zones = [_zone("top", payload)]
+    overrides = {
+        "top": {
+            "hidden_slots": ["slot_missing"],          # absent — no-op
+            "slot_order": ["slot_also_missing"],       # absent — no-op
+        },
+    }
+
+    audit = _apply_structure_overrides_to_zones(overrides, zones)
+
+    assert list(payload.keys()) == ["slot_a"]
+    assert audit["applied_zones"] == 0
+    assert audit["skipped_zones"] == 1
+    assert audit["per_zone"] == [{"position": "top", "mutated": False}]
+
+
+# ─── Case 4 : SCOPE LOCK — frame swap shape dropped at validate ───────
+
+
+def test_frame_swap_keys_dropped_at_validate_no_mutation():
+    payload = {"slot_a": ["A"], "slot_b": ["B"]}
+    zones = [_zone("top", payload)]
+    # frame_id / template_id / slot_payload as inner keys are the canonical
+    # frame-swap / DOM-rebuild shapes the SCOPE LOCK rejects.
+    overrides = {
+        "top": {
+            "frame_id": "MOCK_OTHER_FRAME",
+            "template_id": "MOCK_OTHER_TEMPLATE",
+            "slot_payload": {"slot_a": ["overwritten"]},
+        },
+    }
+
+    audit = _apply_structure_overrides_to_zones(overrides, zones)
+
+    # No mutation: validate gate drops the whole zone payload (no allowed
+    # inner key remains), so the zone never reaches the apply loop.
+    assert payload == {"slot_a": ["A"], "slot_b": ["B"]}
+    assert audit["applied_zones"] == 0
+    assert audit["skipped_zones"] == 0
+    assert audit["per_zone"] == []
+
+
+# ─── Case 5 : raw_content preservation invariant ──────────────────────
+
+
+def test_raw_content_sentinel_untouched():
+    """Helper must not mutate anything outside zone['slot_payload']
+    AND must not mutate per-slot list[str] line content."""
+    raw_sentinel = ["MOCK_S1", "MOCK_S2"]
+    payload = {"slot_a": ["line 1", "line 2"], "slot_b": ["line 3"]}
+    zones = [_zone("top", payload)]
+    zones[0]["source_section_ids_sentinel"] = raw_sentinel  # out-of-band
+    zones[0]["raw_content_sentinel"] = "- line 1\n- line 2\n"
+
+    _apply_structure_overrides_to_zones(
+        {"top": {"slot_order": ["slot_b", "slot_a"]}}, zones,
+    )
+
+    # Out-of-band fields untouched.
+    assert zones[0]["source_section_ids_sentinel"] is raw_sentinel
+    assert zones[0]["source_section_ids_sentinel"] == ["MOCK_S1", "MOCK_S2"]
+    assert zones[0]["raw_content_sentinel"] == "- line 1\n- line 2\n"
+    # Per-slot list[str] line content byte-identical.
+    assert payload["slot_a"] == ["line 1", "line 2"]
+    assert payload["slot_b"] == ["line 3"]
+
+
+# ─── Case 6 : empty / None / irrelevant batch is no-op ────────────────
+
+
+@pytest.mark.parametrize(
+    "batch",
+    [
+        None,
+        {},
+        {"top": {}},                                            # empty per-zone
+        {"missing_zone": {"slot_order": ["slot_a"]}},           # stale zone_id
+    ],
+)
+def test_empty_or_irrelevant_batch_is_noop(batch):
+    payload = {"slot_a": ["A"]}
+    zones = [_zone("top", payload)]
+    audit = _apply_structure_overrides_to_zones(batch, zones)
+
+    assert list(payload.keys()) == ["slot_a"]
+    assert audit["applied_zones"] == 0
+    assert audit["skipped_zones"] == 0
+    assert audit["per_zone"] == []
+
+
+# ─── Case 7 : zone without slot_payload skipped (defensive) ───────────
+
+
+def test_zone_without_slot_payload_skipped():
+    zones = [{"position": "top"}]  # no slot_payload key (defensive contract)
+    audit = _apply_structure_overrides_to_zones(
+        {"top": {"slot_order": ["slot_a"]}}, zones,
+    )
+    assert audit["per_zone"] == []
+    assert audit["applied_zones"] == 0
+    assert audit["skipped_zones"] == 0
+
+
+# ─── Case 8 : combined reorder + hide in a single zone ────────────────
+
+
+def test_combined_reorder_and_hide_in_one_zone():
+    payload = {"slot_a": ["A"], "slot_b": ["B"], "slot_c": ["C"]}
+    zones = [_zone("top", payload)]
+    overrides = {
+        "top": {
+            "hidden_slots": ["slot_b"],
+            "slot_order": ["slot_c", "slot_a"],
+        },
+    }
+
+    audit = _apply_structure_overrides_to_zones(overrides, zones)
+
+    assert list(payload.keys()) == ["slot_c", "slot_a"]
+    assert audit["applied_zones"] == 1
+    assert audit["per_zone"] == [{"position": "top", "mutated": True}]

tests/test_phase_z2_text_overrides.py

@@ -0,0 +1,158 @@
+"""IMP-56 (#90) u5 — Step 12 ``text_overrides`` apply unit tests.
+
+Synthetic — exercises ``_apply_text_overrides_to_zones`` directly without
+running the full Phase Z 22-step pipeline. The helper is decoupled from
+``MdxSection`` / ``CompositionUnit`` graphs and only consumes a minimal
+``[{position, slot_payload}, ...]`` zone list, so a synthetic fixture is
+sufficient to lock the contract.
+
+Coverage axes (Stage 2 plan u5 + Stage 1 binding contract) :
+
+  - sanitized batch : malformed text_path / non-string value drops per-row
+    (mirrors ``image_id_stamper.build_image_overrides_style`` u7 tolerance).
+  - stale path : frame swap / layout regression → ``skipped``, not error.
+  - raw_content preservation : helper never touches ``debug_zones`` / unit
+    graph (asserted by zero-mutation on an out-of-band sentinel mapping).
+  - audit shape : ``applied`` / ``skipped`` / ``per_zone`` keys present and
+    counts consistent with the input batch.
+  - empty / ``None`` override input is a no-op (empty audit).
+
+Fully synthetic per Codex generalization guardrail (MOCK_ prefix).
+NO real catalog template_id / frame_id, NO ``v4_full32_result.yaml``
+dependency.
+"""
+from __future__ import annotations
+
+import pytest
+
+from src.phase_z2_pipeline import _apply_text_overrides_to_zones
+
+
+# ─── Synthetic fixture helpers ──────────────────────────────────────
+
+
+def _zone(position: str, slot_payload: dict) -> dict:
+    """Minimal zone dict mirroring the Step 12 ``zones_data[i]`` shape."""
+    return {
+        "position": position,
+        "template_id": "MOCK_T_phase_z2_text_overrides",
+        "slot_payload": slot_payload,
+        "content_weight": 1.0,
+        "min_height_px": 200,
+    }
+
+
+# ─── Case 1 : happy path — list[str] slot mutation ────────────────────
+
+
+def test_apply_replaces_list_line_in_place():
+    zones = [
+        _zone("top", {"slot_title": ["original headline"], "slot_body": ["a", "b", "c"]}),
+        _zone("bottom", {"slot_caption": ["caption A"]}),
+    ]
+    overrides = {
+        "top": {"slot_title.0": "edited headline", "slot_body.1": "edited B"},
+    }
+
+    audit = _apply_text_overrides_to_zones(overrides, zones)
+
+    assert zones[0]["slot_payload"]["slot_title"] == ["edited headline"]
+    assert zones[0]["slot_payload"]["slot_body"] == ["a", "edited B", "c"]
+    # bottom zone untouched (no override entry)
+    assert zones[1]["slot_payload"]["slot_caption"] == ["caption A"]
+    assert audit["applied"] == 2
+    assert audit["skipped"] == 0
+    assert audit["per_zone"] == [{"position": "top", "applied": 2, "skipped": 0}]
+
+
+# ─── Case 2 : stale text_path — frame swap / layout regression ────────
+
+
+def test_stale_text_path_skipped_silently():
+    """Absent slot_key + out-of-range line_index both count as skipped, not errors."""
+    zones = [_zone("top", {"slot_title": ["only one line"]})]
+    overrides = {
+        "top": {
+            "slot_title.0": "ok",           # applied
+            "slot_title.99": "out of range", # skipped (idx > len)
+            "slot_missing.0": "stale frame", # skipped (slot absent)
+        },
+    }
+
+    audit = _apply_text_overrides_to_zones(overrides, zones)
+
+    assert zones[0]["slot_payload"]["slot_title"] == ["ok"]
+    assert "slot_missing" not in zones[0]["slot_payload"]
+    assert audit["applied"] == 1
+    assert audit["skipped"] == 2
+    assert audit["per_zone"][0] == {"position": "top", "applied": 1, "skipped": 2}
+
+
+# ─── Case 3 : malformed input — per-entry tolerance ────────────────────
+
+
+def test_malformed_entries_dropped_in_validate():
+    """Non-string value / malformed text_path drop in ``validate_text_overrides``."""
+    zones = [_zone("top", {"slot_title": ["original", "second"]})]
+    overrides = {
+        "top": {
+            "slot_title.0": "good",        # kept
+            "slot_title.bad": "ignored",   # dropped (non-int idx)
+            "slot_title.1": 123,           # dropped (non-str value)
+            "no_dot": "ignored",           # dropped (missing '.')
+        },
+        "": {"slot_title.0": "empty zone id dropped"},  # zone_id sanitization
+        123: {"slot_title.0": "non-string zone id dropped"},
+    }
+
+    audit = _apply_text_overrides_to_zones(overrides, zones)
+
+    # only the well-formed entry applied
+    assert zones[0]["slot_payload"]["slot_title"] == ["good", "second"]
+    assert audit["applied"] == 1
+    assert audit["skipped"] == 0
+
+
+# ─── Case 4 : raw_content preservation invariant ──────────────────────
+
+
+def test_raw_content_sentinel_untouched():
+    """Helper must not mutate anything outside ``zone['slot_payload']``.
+
+    Out-of-band fields (mirror of ``debug_zones[i].source_section_ids`` /
+    MdxSection graph) stay byte-identical — Stage 1 binding contract.
+    """
+    raw_sentinel = ["MOCK_S1", "MOCK_S2"]
+    zones = [_zone("top", {"slot_title": ["original"]})]
+    zones[0]["source_section_ids_sentinel"] = raw_sentinel  # out-of-band
+    zones[0]["raw_content_sentinel"] = "- original bullet\n- second\n"
+
+    _apply_text_overrides_to_zones({"top": {"slot_title.0": "edited"}}, zones)
+
+    assert zones[0]["source_section_ids_sentinel"] is raw_sentinel  # same object
+    assert zones[0]["source_section_ids_sentinel"] == ["MOCK_S1", "MOCK_S2"]
+    assert zones[0]["raw_content_sentinel"] == "- original bullet\n- second\n"
+
+
+# ─── Case 5 : empty / None batch is no-op ──────────────────────────────
+
+
+@pytest.mark.parametrize("payload", [None, {}, {"top": {}}, {"missing_zone": {"slot.0": "x"}}])
+def test_empty_or_irrelevant_batch_is_noop(payload):
+    zones = [_zone("top", {"slot_title": ["unchanged"]})]
+    audit = _apply_text_overrides_to_zones(payload, zones)
+
+    assert zones[0]["slot_payload"]["slot_title"] == ["unchanged"]
+    assert audit["applied"] == 0
+    assert audit["skipped"] == 0
+
+
+# ─── Case 6 : zone without slot_payload skipped (defensive) ───────────
+
+
+def test_zone_without_slot_payload_skipped():
+    zones = [{"position": "top"}]  # no slot_payload key (defensive contract)
+    audit = _apply_text_overrides_to_zones({"top": {"slot.0": "x"}}, zones)
+    assert audit["per_zone"] == []
+    assert audit["applied"] == 0
+    assert audit["skipped"] == 0

tests/test_phase_z2_text_path_stamper.py

@@ -0,0 +1,212 @@
+"""IMP-56 (#90) u9 — Step 13 ``text_path_stamper`` wiring tests.
+
+Verifies that :func:`src.phase_z2_pipeline.render_slide` stamps each
+rendered ``text-line`` opening tag with
+``data-text-path="{slot_key}.{line_index}"`` via the u8 stamper
+(``src.text_path_stamper.stamp_zone_html``). This is the wiring unit
+companion to the u8 module-level tests at
+``tests/test_text_path_stamper.py``.
+
+Coverage axes (Stage 2 plan u9 + Stage 1 binding contract) :
+
+  - happy path : real ``bim_current_problems_paired`` template emits
+    ``text-line`` divs for list-valued slots; the stamper attaches
+    ``data-text-path`` with matching ``{slot_key}.{line_index}``.
+  - non-list slots skipped : ``title`` / ``row_*_left_label`` (scalars)
+    do NOT receive ``data-text-path`` attributes.
+  - empty list slots emit no stamps : rows whose body list is empty
+    contribute zero stamps.
+  - deterministic : repeated calls produce byte-identical HTML
+    (no nondeterministic mutation of ``slot_payload`` between renders).
+  - empty zone : the ``__empty__`` template_id short-circuit emits no
+    ``data-text-path`` (the stamper short-circuits on empty stamps).
+
+Fully synthetic slot_payload — no real Phase Z run, no
+``v4_full32_result.yaml`` dependency. Uses the real
+``bim_current_problems_paired`` family template only to exercise the
+genuine Jinja2 + slide_base render path.
+"""
+from __future__ import annotations
+
+import re
+
+import pytest
+
+from src.phase_z2_pipeline import render_slide
+
+
+# ─── Fixture helpers ────────────────────────────────────────────────
+
+
+def _layout_css() -> dict:
+    """Minimal valid layout_css for a single-zone slide.
+
+    Mirrors tests/phase_z2/test_slide_base_embedded_mode.py shape.
+    """
+    return {"areas": '"primary"', "cols": "1fr", "rows": "1fr"}
+
+
+def _paired_slot_payload(
+    *,
+    left_lines: list[str] | None = None,
+    right_lines: list[str] | None = None,
+) -> dict:
+    """Build a slot_payload for the bim_current_problems_paired family.
+
+    Only row_1 is populated by default; rows 2-4 stay empty so the
+    template short-circuits to zero text-line divs for them.
+    """
+    left_lines = left_lines if left_lines is not None else ["L1a", "L1b"]
+    right_lines = right_lines if right_lines is not None else ["R1a"]
+    payload: dict = {
+        "title": "Synthetic Title",
+        "row_1_left_label": "left pill 1",
+        "row_1_left_body": [{"text": t, "indent": 0} for t in left_lines],
+        "row_1_right_label": "right pill 1",
+        "row_1_right_body": [{"text": t, "indent": 0} for t in right_lines],
+    }
+    for r in (2, 3, 4):
+        payload[f"row_{r}_left_label"] = f"left pill {r}"
+        payload[f"row_{r}_left_body"] = []
+        payload[f"row_{r}_right_label"] = f"right pill {r}"
+        payload[f"row_{r}_right_body"] = []
+    return payload
+
+
+def _zone(template_id: str, slot_payload: dict) -> dict:
+    return {
+        "position": "primary",
+        "template_id": template_id,
+        "slot_payload": slot_payload,
+    }
+
+
+def _render(zones: list[dict]) -> str:
+    return render_slide(
+        slide_title="t",
+        slide_footer=None,
+        zones_data=zones,
+        layout_preset="single",
+        layout_css=_layout_css(),
+        gap_px=14,
+        embedded_mode="embedded",
+    )
+
+
+# ─── Case 1 : happy path — list-valued slots stamped ─────────────────
+
+
+def test_render_slide_stamps_text_path_per_line():
+    """Each list-valued slot line gets data-text-path={slot}.{index}."""
+    payload = _paired_slot_payload(
+        left_lines=["left line A", "left line B"],
+        right_lines=["right line A"],
+    )
+    html = _render([_zone("bim_current_problems_paired", payload)])
+
+    # left body 2 lines + right body 1 line = 3 stamps in row 1.
+    assert 'data-text-path="row_1_left_body.0"' in html
+    assert 'data-text-path="row_1_left_body.1"' in html
+    assert 'data-text-path="row_1_right_body.0"' in html
+    # row 2-4 are empty → no stamps for those slot_keys.
+    assert "row_2_left_body" not in html
+    assert "row_3_right_body" not in html
+
+
+def test_stamps_preserve_class_attribute():
+    """data-text-path injected before existing class attribute, both present."""
+    payload = _paired_slot_payload(left_lines=["only left"], right_lines=[])
+    html = _render([_zone("bim_current_problems_paired", payload)])
+
+    # The original class="text-line..." must survive verbatim alongside
+    # the injected data-text-path attribute on the same opening tag.
+    assert re.search(
+        r'<div\s+data-text-path="row_1_left_body\.0"\s+class="text-line[^"]*">',
+        html,
+    ) is not None
+
+
+# ─── Case 2 : non-list slots are NOT stamped ─────────────────────────
+
+
+def test_non_list_slots_not_stamped():
+    """Scalar slot values (title, *_label) get no data-text-path."""
+    payload = _paired_slot_payload(left_lines=["x"], right_lines=["y"])
+    html = _render([_zone("bim_current_problems_paired", payload)])
+
+    # Scalar slots present in slot_payload as strings — must not receive
+    # data-text-path stamps (u8 contract: scalar slots skipped silently
+    # because they render outside text-line divs).
+    assert 'data-text-path="title' not in html
+    assert 'data-text-path="row_1_left_label' not in html
+    assert 'data-text-path="row_1_right_label' not in html
+
+
+# ─── Case 3 : empty list slots contribute no stamps ──────────────────
+
+
+def test_empty_list_slots_no_stamps():
+    """Empty list slot yields zero stamps; template emits zero text-line divs."""
+    payload = _paired_slot_payload(left_lines=[], right_lines=[])
+    html = _render([_zone("bim_current_problems_paired", payload)])
+
+    # No row 1 lines at all (both bodies empty) → no row_1_*_body stamps.
+    assert "data-text-path" not in html
+
+
+# ─── Case 4 : deterministic — repeated render produces same HTML ─────
+
+
+def test_render_with_stamp_is_deterministic():
+    """Same slot_payload → byte-identical HTML across two render_slide calls.
+
+    Guards against the wiring layer accidentally mutating slot_payload
+    between renders (the stamper itself only reads slot_payload; it
+    operates on rendered_partial). Also guards against double-stamping.
+    """
+    payload_1 = _paired_slot_payload()
+    payload_2 = _paired_slot_payload()
+    html_1 = _render([_zone("bim_current_problems_paired", payload_1)])
+    html_2 = _render([_zone("bim_current_problems_paired", payload_2)])
+
+    assert html_1 == html_2
+    # Counts must match — no double-stamp side effect on shared module state.
+    assert html_1.count("data-text-path=") == html_2.count("data-text-path=")
+    # 2 left + 1 right = 3 stamps for the default fixture.
+    assert html_1.count("data-text-path=") == 3
+
+
+# ─── Case 5 : __empty__ short-circuit emits no stamps ────────────────
+
+
+def test_empty_template_short_circuit_no_stamps():
+    """``template_id=__empty__`` short-circuits before stamping; no stamps."""
+    html = _render([_zone("__empty__", {})])
+    assert "data-text-path" not in html
+
+
+# ─── Case 6 : slot_payload preserved (raw_content invariant) ─────────
+
+
+def test_render_does_not_mutate_slot_payload():
+    """Stamping must not mutate slot_payload list/dict contents.
+
+    The stamper operates on rendered_partial HTML; the source
+    slot_payload should be byte-identical before and after render_slide.
+    Locks the raw_content preservation invariant at the wiring layer.
+    """
+    payload = _paired_slot_payload(
+        left_lines=["preserved A", "preserved B"],
+        right_lines=["preserved C"],
+    )
+    # Snapshot key list/dict identities and content.
+    snapshot_left = list(payload["row_1_left_body"])
+    snapshot_left_text = [item["text"] for item in snapshot_left]
+    snapshot_right_text = [item["text"] for item in payload["row_1_right_body"]]
+
+    _ = _render([_zone("bim_current_problems_paired", payload)])
+
+    assert [item["text"] for item in payload["row_1_left_body"]] == snapshot_left_text
+    assert [item["text"] for item in payload["row_1_right_body"]] == snapshot_right_text
+    # Scalar slots untouched too.
+    assert payload["title"] == "Synthetic Title"

tests/test_structure_override_resolver.py

@@ -0,0 +1,392 @@
+"""IMP-56 (#90) u6 — tests for ``src.structure_override_resolver``.
+
+Covers the resolver contract called out in the Stage 2 plan :
+
+1. ``validate_structure_overrides`` returns ``{}`` for non-mapping input.
+2. ``validate_structure_overrides`` preserves well-formed entries.
+3. ``validate_structure_overrides`` drops malformed per-entry rows without
+   rejecting the whole batch (per-entry tolerance — mirrors u4
+   text_override_resolver contract).
+4. ``validate_structure_overrides`` REJECTS frame swap (any inner key
+   other than slot_order / hidden_slots is silently dropped — SCOPE LOCK).
+5. ``validate_structure_overrides`` drops non-list slot_order / hidden_slots
+   values.
+6. ``validate_structure_overrides`` drops non-string or empty slot_keys
+   inside slot_order / hidden_slots.
+7. ``validate_structure_overrides`` de-duplicates slot_key entries within
+   each list.
+8. ``validate_structure_overrides`` returns fresh nested dicts AND lists
+   (caller can mutate without aliasing the source).
+9. ``validate_structure_overrides`` drops per-zone payloads that contain
+   neither a non-empty slot_order nor a non-empty hidden_slots after
+   sanitization.
+10. ``apply_structure_override`` removes hidden_slots in-place and returns
+    ``True``.
+11. ``apply_structure_override`` reorders the slot-payload mapping per
+    slot_order (partial reorder; unmentioned slots keep tail order).
+12. ``apply_structure_override`` combines hide + reorder atomically.
+13. ``apply_structure_override`` silently skips stale slot_keys (frame
+    swap / layout regression) without raising.
+14. ``apply_structure_override`` returns ``False`` (no mutation) on a
+    no-op override (empty, or all stale).
+15. ``apply_structure_override`` preserves the caller's reference identity
+    on ``zone`` (in-place mutation via clear + update).
+16. ``apply_structure_override`` NEVER inspects or mutates per-slot
+    payload values — only top-level key membership / ordering.
+17. ``apply_structure_override`` is defensive against non-list
+    slot_order / hidden_slots leaking through (treats as empty, no raise).
+
+All tests are pure-Python — no filesystem, no Selenium, no fixtures.
+"""
+from __future__ import annotations
+
+from src.structure_override_resolver import (
+    InvalidStructureOverride,
+    apply_structure_override,
+    validate_structure_overrides,
+)
+
+
+# -- module surface ---------------------------------------------------------
+
+
+def test_invalid_structure_override_is_value_error_subclass():
+    # Reserved future strict-mode exception — kept as a public surface so
+    # u7 / strict callers can branch on source-malformation vs stale-DOM.
+    assert issubclass(InvalidStructureOverride, ValueError)
+
+
+# -- validate_structure_overrides ------------------------------------------
+
+
+def test_validate_structure_overrides_non_mapping_returns_empty():
+    for bad_input in [None, [], "string", 42, 1.5]:
+        assert validate_structure_overrides(bad_input) == {}
+
+
+def test_validate_structure_overrides_passes_well_formed():
+    payload = {
+        "zone-top": {
+            "slot_order": ["slot_title", "slot_body"],
+            "hidden_slots": ["slot_caption"],
+        },
+        "zone-bottom": {"slot_order": ["slot_a", "slot_b"]},
+        "zone-only-hide": {"hidden_slots": ["slot_x"]},
+    }
+    out = validate_structure_overrides(payload)
+    assert out == {
+        "zone-top": {
+            "slot_order": ["slot_title", "slot_body"],
+            "hidden_slots": ["slot_caption"],
+        },
+        "zone-bottom": {"slot_order": ["slot_a", "slot_b"]},
+        "zone-only-hide": {"hidden_slots": ["slot_x"]},
+    }
+    assert out is not payload  # fresh dict
+
+
+def test_validate_structure_overrides_per_entry_tolerance():
+    payload = {
+        "zone-top": {
+            "slot_order": ["slot_title", "slot_body"],
+            "hidden_slots": ["slot_caption"],
+        },
+        "": {"slot_order": ["x"]},  # empty zone_id dropped
+        42: {"slot_order": ["y"]},  # non-string zone_id dropped
+        "zone-non-mapping": "not a dict",  # non-mapping payload dropped
+        "zone-bottom": {"hidden_slots": ["slot_aux"]},
+    }
+    out = validate_structure_overrides(payload)
+    assert out == {
+        "zone-top": {
+            "slot_order": ["slot_title", "slot_body"],
+            "hidden_slots": ["slot_caption"],
+        },
+        "zone-bottom": {"hidden_slots": ["slot_aux"]},
+    }
+
+
+def test_validate_structure_overrides_rejects_frame_swap_inner_keys():
+    # SCOPE LOCK — frame swap attempts MUST be silently dropped. The only
+    # mechanism for swapping a frame is the existing ``frames`` axis; this
+    # resolver intentionally has no escape hatch so the Phase Z
+    # no-AI-HTML-structure invariant stays intact.
+    payload = {
+        "zone-top": {
+            "slot_order": ["slot_title"],
+            # The following 4 keys are all frame-swap / DOM-rebuild
+            # attempts and MUST be dropped by validate.
+            "frame_id": "compare_v2",
+            "template_id": "topic_left_right",
+            "unit_id": "03-1+03-2",
+            "slot_payload": {"injected_slot": ["unsafe"]},
+        },
+    }
+    out = validate_structure_overrides(payload)
+    assert out == {"zone-top": {"slot_order": ["slot_title"]}}
+
+
+def test_validate_structure_overrides_rejects_frame_swap_zone_with_no_lock_keys():
+    # If a per-zone payload contains ONLY frame-swap attempts (no
+    # slot_order / hidden_slots), the whole zone gets dropped after
+    # sanitization (no signal remains).
+    payload = {
+        "zone-attempt-swap": {
+            "frame_id": "compare_v2",
+            "template_id": "topic_left_right",
+        },
+    }
+    out = validate_structure_overrides(payload)
+    assert out == {}
+
+
+def test_validate_structure_overrides_drops_non_list_slot_arrays():
+    payload = {
+        "zone-top": {
+            "slot_order": "not a list",
+            "hidden_slots": {"also": "not a list"},
+        },
+        "zone-bottom": {
+            "slot_order": 42,
+            "hidden_slots": None,
+        },
+        "zone-good": {"slot_order": ["slot_title"]},
+    }
+    out = validate_structure_overrides(payload)
+    assert out == {"zone-good": {"slot_order": ["slot_title"]}}
+
+
+def test_validate_structure_overrides_drops_bad_slot_key_entries():
+    payload = {
+        "zone-top": {
+            "slot_order": [
+                "good_slot",
+                "",  # empty string dropped
+                42,  # non-string dropped
+                None,  # non-string dropped
+                {"nested": "obj"},  # non-string dropped
+                "another_good",
+            ],
+            "hidden_slots": ["", "valid_hide", 99, "valid_hide_2"],
+        },
+    }
+    out = validate_structure_overrides(payload)
+    assert out == {
+        "zone-top": {
+            "slot_order": ["good_slot", "another_good"],
+            "hidden_slots": ["valid_hide", "valid_hide_2"],
+        },
+    }
+
+
+def test_validate_structure_overrides_dedupes_slot_key_entries():
+    payload = {
+        "zone-top": {
+            "slot_order": ["a", "b", "a", "c", "b"],
+            "hidden_slots": ["x", "x", "y", "x"],
+        },
+    }
+    out = validate_structure_overrides(payload)
+    assert out == {
+        "zone-top": {
+            "slot_order": ["a", "b", "c"],
+            "hidden_slots": ["x", "y"],
+        },
+    }
+
+
+def test_validate_structure_overrides_drops_empty_payload_after_sanitization():
+    # Per-zone payloads that have empty slot_order AND empty hidden_slots
+    # after sanitization carry no signal → drop the zone entirely.
+    payload = {
+        "zone-empty-lists": {"slot_order": [], "hidden_slots": []},
+        "zone-only-bad-entries": {"slot_order": ["", None, 99]},
+        "zone-good": {"slot_order": ["slot_title"]},
+    }
+    out = validate_structure_overrides(payload)
+    assert out == {"zone-good": {"slot_order": ["slot_title"]}}
+
+
+def test_validate_structure_overrides_returns_fresh_nested_dicts_and_lists():
+    # Mutating the returned dict's per-zone payload (or any list inside)
+    # must not leak back into the source.
+    payload = {
+        "zone-top": {
+            "slot_order": ["a", "b"],
+            "hidden_slots": ["x"],
+        },
+    }
+    out = validate_structure_overrides(payload)
+    out["zone-top"]["slot_order"].append("mutated")
+    out["zone-top"]["hidden_slots"].append("mutated_hide")
+    out["zone-top"]["new_key"] = "leaked?"
+    assert payload["zone-top"]["slot_order"] == ["a", "b"]
+    assert payload["zone-top"]["hidden_slots"] == ["x"]
+    assert "new_key" not in payload["zone-top"]
+
+
+# -- apply_structure_override ----------------------------------------------
+
+
+def test_apply_structure_override_hide_only_mutates_in_place():
+    zone: dict = {
+        "slot_title": ["title line"],
+        "slot_body": ["body line"],
+        "slot_caption": ["caption"],
+    }
+    assert apply_structure_override(zone, {"hidden_slots": ["slot_caption"]}) is True
+    assert list(zone.keys()) == ["slot_title", "slot_body"]
+    assert zone == {
+        "slot_title": ["title line"],
+        "slot_body": ["body line"],
+    }
+
+
+def test_apply_structure_override_reorder_only_partial():
+    # Partial reorder — listed keys move to front in order; unmentioned
+    # keys keep their original relative order at the tail.
+    zone: dict = {
+        "slot_title": ["t"],
+        "slot_body": ["b"],
+        "slot_caption": ["c"],
+        "slot_aux": ["a"],
+    }
+    assert apply_structure_override(zone, {"slot_order": ["slot_aux", "slot_title"]}) is True
+    assert list(zone.keys()) == ["slot_aux", "slot_title", "slot_body", "slot_caption"]
+
+
+def test_apply_structure_override_combines_hide_and_reorder():
+    zone: dict = {
+        "slot_title": ["t"],
+        "slot_body": ["b"],
+        "slot_caption": ["c"],
+        "slot_aux": ["a"],
+    }
+    override = {
+        "slot_order": ["slot_aux", "slot_body"],
+        "hidden_slots": ["slot_caption"],
+    }
+    assert apply_structure_override(zone, override) is True
+    # slot_caption hidden; slot_aux + slot_body moved to front; remaining
+    # (slot_title) appended at tail in original order.
+    assert list(zone.keys()) == ["slot_aux", "slot_body", "slot_title"]
+
+
+def test_apply_structure_override_silently_skips_stale_slot_keys():
+    # Frame swap / layout regression — the prior render's override
+    # references slot_keys that the new render's frame no longer emits.
+    # The resolver must silently skip those without raising.
+    zone: dict = {"slot_title": ["t"], "slot_body": ["b"]}
+    override = {
+        "slot_order": ["slot_phantom_1", "slot_body", "slot_phantom_2"],
+        "hidden_slots": ["slot_does_not_exist"],
+    }
+    assert apply_structure_override(zone, override) is True
+    # slot_body moves to front; slot_title appended at tail; phantoms
+    # silently ignored; hidden_slots no-op.
+    assert list(zone.keys()) == ["slot_body", "slot_title"]
+    assert zone == {"slot_body": ["b"], "slot_title": ["t"]}
+
+
+def test_apply_structure_override_no_op_returns_false():
+    # Empty override → no mutation.
+    zone: dict = {"slot_title": ["t"], "slot_body": ["b"]}
+    snapshot = dict(zone)
+    assert apply_structure_override(zone, {}) is False
+    assert zone == snapshot
+    assert list(zone.keys()) == ["slot_title", "slot_body"]
+
+
+def test_apply_structure_override_all_stale_returns_false():
+    # All slot_keys in the override are absent from zone → no mutation.
+    zone: dict = {"slot_title": ["t"], "slot_body": ["b"]}
+    snapshot = dict(zone)
+    override = {
+        "slot_order": ["phantom_a", "phantom_b"],
+        "hidden_slots": ["phantom_c"],
+    }
+    assert apply_structure_override(zone, override) is False
+    assert zone == snapshot
+    assert list(zone.keys()) == ["slot_title", "slot_body"]
+
+
+def test_apply_structure_override_already_in_desired_order_returns_false():
+    # slot_order matches the existing key order exactly → no mutation.
+    zone: dict = {"slot_title": ["t"], "slot_body": ["b"]}
+    override = {"slot_order": ["slot_title", "slot_body"]}
+    assert apply_structure_override(zone, override) is False
+    assert list(zone.keys()) == ["slot_title", "slot_body"]
+
+
+def test_apply_structure_override_preserves_zone_reference_identity():
+    # In-place mutation via clear + update — caller's reference must
+    # remain valid after reorder.
+    zone: dict = {"slot_a": ["a"], "slot_b": ["b"], "slot_c": ["c"]}
+    zone_ref = zone  # capture reference
+    apply_structure_override(zone, {"slot_order": ["slot_c", "slot_a"]})
+    assert zone_ref is zone
+    assert list(zone.keys()) == ["slot_c", "slot_a", "slot_b"]
+
+
+def test_apply_structure_override_never_inspects_per_slot_values():
+    # The resolver MUST NOT inspect / mutate per-slot list[str] contents.
+    # Use weird non-list values to confirm passthrough.
+    zone: dict = {
+        "slot_a": ["a1", "a2", "a3"],
+        "slot_b": {"nested": "object"},  # non-list payload — passthrough
+        "slot_c": None,  # None payload — passthrough
+        "slot_d": 42,  # int payload — passthrough
+    }
+    snapshot = {k: zone[k] for k in zone}
+    apply_structure_override(zone, {"slot_order": ["slot_d", "slot_a"]})
+    assert list(zone.keys()) == ["slot_d", "slot_a", "slot_b", "slot_c"]
+    # values are identity-preserved
+    for key in zone:
+        assert zone[key] is snapshot[key]
+
+
+def test_apply_structure_override_defensive_on_non_list_arrays():
+    # If a non-validated override leaks through, non-list slot_order /
+    # hidden_slots should be treated as empty rather than raising.
+    zone: dict = {"slot_title": ["t"], "slot_body": ["b"]}
+    snapshot = dict(zone)
+    override = {
+        "slot_order": "not a list",
+        "hidden_slots": {"also": "not a list"},
+    }
+    assert apply_structure_override(zone, override) is False
+    assert zone == snapshot
+    assert list(zone.keys()) == ["slot_title", "slot_body"]
+
+
+def test_apply_structure_override_hide_wins_over_reorder():
+    # Edge case: a slot_key appears in BOTH slot_order and hidden_slots.
+    # hidden_slots is applied first, so the slot is gone by the time
+    # reorder runs — the reorder entry silently no-ops.
+    zone: dict = {"slot_a": ["a"], "slot_b": ["b"], "slot_c": ["c"]}
+    override = {
+        "slot_order": ["slot_b", "slot_a", "slot_c"],
+        "hidden_slots": ["slot_b"],
+    }
+    assert apply_structure_override(zone, override) is True
+    # slot_b removed first; slot_a + slot_c reordered to front (slot_b
+    # silently skipped because it no longer exists).
+    assert list(zone.keys()) == ["slot_a", "slot_c"]
+
+
+def test_apply_structure_override_returns_true_on_pure_reorder_only():
+    # Pure reorder (no hide) — should still return True when key order
+    # actually changes.
+    zone: dict = {"slot_a": ["a"], "slot_b": ["b"]}
+    override = {"slot_order": ["slot_b", "slot_a"]}
+    assert apply_structure_override(zone, override) is True
+    assert list(zone.keys()) == ["slot_b", "slot_a"]
+
+
+def test_apply_structure_override_returns_true_on_pure_hide_only():
+    # Pure hide (no reorder) — should still return True when a key was
+    # actually removed.
+    zone: dict = {"slot_a": ["a"], "slot_b": ["b"]}
+    override = {"hidden_slots": ["slot_a"]}
+    assert apply_structure_override(zone, override) is True
+    assert list(zone.keys()) == ["slot_b"]

tests/test_text_override_resolver.py

@@ -0,0 +1,188 @@
+"""IMP-56 (#90) u4 — tests for ``src.text_override_resolver``.
+
+Covers the resolver contract called out in the Stage 2 plan :
+
+1. ``parse_text_path`` happy path : ``slot_title.0`` → ``("slot_title", 0)``.
+2. ``parse_text_path`` rejects: empty / non-string / no '.' / negative
+   index / non-int index / empty slot_key / empty line_index.
+3. ``parse_text_path`` ``rpartition`` semantics — compound slot_key with
+   internal '.' is preserved (split is on LAST '.').
+4. ``validate_text_overrides`` returns ``{}`` for non-mapping input.
+5. ``validate_text_overrides`` drops malformed per-entry rows without
+   rejecting the whole batch (mirrors image_id_stamper per-entry tolerance).
+6. ``validate_text_overrides`` preserves well-formed entries.
+7. ``validate_text_overrides`` returns a fresh dict (caller can mutate
+   without aliasing the source).
+8. ``apply_text_override`` happy path mutates in-place and returns ``True``.
+9. ``apply_text_override`` returns ``False`` (no mutation) on absent slot.
+10. ``apply_text_override`` returns ``False`` (no mutation) on
+    line_index >= len(lines) (forward-compat with frame swap / layout
+    regression dropping the slot row).
+11. ``apply_text_override`` returns ``False`` (no mutation) on a
+    non-list slot (defensive against malformed zone wrappers).
+12. ``apply_text_override`` preserves untouched lines / other slots.
+
+All tests are pure-Python — no filesystem, no Selenium, no fixtures.
+"""
+from __future__ import annotations
+
+import pytest
+
+from src.text_override_resolver import (
+    InvalidTextOverride,
+    apply_text_override,
+    parse_text_path,
+    validate_text_overrides,
+)
+
+
+# -- parse_text_path --------------------------------------------------------
+
+
+def test_parse_text_path_simple():
+    assert parse_text_path("slot_title.0") == ("slot_title", 0)
+    assert parse_text_path("slot_body.5") == ("slot_body", 5)
+
+
+def test_parse_text_path_compound_slot_key():
+    # rpartition semantics — split on LAST '.' so compound keys survive.
+    # Note: a numeric-looking compound suffix (e.g., 'slot.1.5') parses to
+    # ('slot.1', 5) by design; callers that want a strict identifier-only
+    # slot_key should enforce that in their own stamper (u8).
+    assert parse_text_path("slot.compound.2") == ("slot.compound", 2)
+    assert parse_text_path("slot_title.1.5") == ("slot_title.1", 5)
+
+
+@pytest.mark.parametrize(
+    "bad_path",
+    [
+        "",
+        "no_dot",
+        ".0",
+        "slot_title.",
+        "slot_title.-1",
+        "slot_title.abc",
+    ],
+)
+def test_parse_text_path_rejects_malformed(bad_path):
+    with pytest.raises(InvalidTextOverride):
+        parse_text_path(bad_path)
+
+
+@pytest.mark.parametrize("bad_type", [None, 0, 1.5, [], {}, b"slot.0"])
+def test_parse_text_path_rejects_non_string(bad_type):
+    with pytest.raises(InvalidTextOverride):
+        parse_text_path(bad_type)  # type: ignore[arg-type]
+
+
+# -- validate_text_overrides ------------------------------------------------
+
+
+@pytest.mark.parametrize("bad_input", [None, [], "string", 42, 1.5])
+def test_validate_text_overrides_non_mapping_returns_empty(bad_input):
+    assert validate_text_overrides(bad_input) == {}
+
+
+def test_validate_text_overrides_passes_well_formed():
+    payload = {
+        "zone-top": {"slot_title.0": "edited headline"},
+        "zone-bottom": {"slot_body.0": "line A", "slot_body.1": "line B"},
+    }
+    out = validate_text_overrides(payload)
+    assert out == payload
+    assert out is not payload  # fresh dict
+
+
+def test_validate_text_overrides_per_entry_tolerance():
+    # Mix of well-formed + every variety of malformed; only the well-formed
+    # rows should survive.
+    payload = {
+        "zone-top": {
+            "slot_title.0": "good",
+            "no_dot": "bad path",
+            "slot_x.abc": "bad index",
+            "slot_y.-1": "negative",
+            42: "non-string path",
+            "slot_z.0": 99,  # non-string value
+        },
+        "": {"slot_title.0": "bad zone id"},  # empty zone_id dropped
+        42: {"slot_title.0": "non-string zone id"},  # non-string dropped
+        "zone-empty-after-filter": {"no_dot": "x"},  # entire zone drops
+        "zone-non-mapping": "not a dict",  # non-mapping dropped
+        "zone-bottom": {"slot_body.0": "kept"},
+    }
+    out = validate_text_overrides(payload)
+    assert out == {
+        "zone-top": {"slot_title.0": "good"},
+        "zone-bottom": {"slot_body.0": "kept"},
+    }
+
+
+def test_validate_text_overrides_returns_fresh_nested_dicts():
+    # Mutating the returned dict's per-zone payload must not leak back
+    # into the source (callers should be able to use the result as a
+    # working buffer).
+    payload = {"zone-top": {"slot_title.0": "v"}}
+    out = validate_text_overrides(payload)
+    out["zone-top"]["slot_title.0"] = "mutated"
+    assert payload["zone-top"]["slot_title.0"] == "v"
+
+
+# -- apply_text_override ----------------------------------------------------
+
+
+def test_apply_text_override_happy_path_mutates_in_place():
+    zone: dict = {"slot_title": ["orig"]}
+    assert apply_text_override(zone, "slot_title.0", "edited") is True
+    assert zone == {"slot_title": ["edited"]}
+
+
+def test_apply_text_override_multi_line_slot():
+    zone: dict = {"slot_body": ["line A", "line B", "line C"]}
+    assert apply_text_override(zone, "slot_body.1", "REPLACED") is True
+    assert zone == {"slot_body": ["line A", "REPLACED", "line C"]}
+
+
+def test_apply_text_override_absent_slot_returns_false_no_mutation():
+    zone: dict = {"slot_title": ["orig"]}
+    assert apply_text_override(zone, "slot_missing.0", "x") is False
+    assert zone == {"slot_title": ["orig"]}
+
+
+def test_apply_text_override_out_of_range_returns_false_no_mutation():
+    # Forward-compat: a prior render's text_path may target an index the
+    # new render's slot no longer emits (frame swap / layout regression).
+    # This is NOT an error — the override is silently skipped.
+    zone: dict = {"slot_body": ["only one line"]}
+    assert apply_text_override(zone, "slot_body.5", "x") is False
+    assert zone == {"slot_body": ["only one line"]}
+
+
+def test_apply_text_override_non_list_slot_returns_false_no_mutation():
+    # Defensive: if a wrapper passes a non-list slot value, do not crash.
+    zone: dict = {"slot_title": "not a list"}
+    assert apply_text_override(zone, "slot_title.0", "x") is False
+    assert zone == {"slot_title": "not a list"}
+
+
+def test_apply_text_override_preserves_other_slots_and_lines():
+    zone: dict = {
+        "slot_title": ["title line"],
+        "slot_body": ["body line A", "body line B"],
+        "slot_caption": ["caption"],
+    }
+    assert apply_text_override(zone, "slot_body.0", "EDITED A") is True
+    assert zone == {
+        "slot_title": ["title line"],  # untouched
+        "slot_body": ["EDITED A", "body line B"],  # only line 0 changed
+        "slot_caption": ["caption"],  # untouched
+    }
+
+
+def test_apply_text_override_propagates_parse_errors():
+    # apply delegates path parsing to parse_text_path; malformed paths
+    # raise (NOT return False) so callers can distinguish "skipped because
+    # path didn't match the live DOM" from "path was malformed at source".
+    zone: dict = {"slot_title": ["x"]}
+    with pytest.raises(InvalidTextOverride):
+        apply_text_override(zone, "no_dot", "x")

tests/test_text_path_stamper.py

@@ -0,0 +1,307 @@
+"""IMP-56 (#90) u8 — scoped tests for src.text_path_stamper.
+
+Covers: path formatting, slot iteration, DOM injection, idempotence,
+excess-element handling, compound slot keys, and inverse symmetry with
+src.text_override_resolver.parse_text_path.
+"""
+from __future__ import annotations
+
+import pytest
+
+from src.text_override_resolver import parse_text_path
+from src.text_path_stamper import (
+    TEXT_PATH_ATTR,
+    build_text_path,
+    iter_zone_stamps,
+    stamp_zone_html,
+)
+
+
+# ─── build_text_path ──────────────────────────────────────────────────────
+
+
+def test_build_text_path_basic():
+    assert build_text_path("slot_title", 0) == "slot_title.0"
+
+
+def test_build_text_path_nonzero_index():
+    assert build_text_path("row_3_left_body", 5) == "row_3_left_body.5"
+
+
+def test_build_text_path_compound_slot_key():
+    # slot_key may itself contain '.'; parse_text_path uses rpartition.
+    path = build_text_path("group.slot.compound", 2)
+    assert path == "group.slot.compound.2"
+    slot_key, line_index = parse_text_path(path)
+    assert slot_key == "group.slot.compound"
+    assert line_index == 2
+
+
+def test_build_text_path_round_trip_with_resolver():
+    # Inverse symmetry with src.text_override_resolver.parse_text_path.
+    for slot_key, idx in [
+        ("title", 0),
+        ("row_1_left_body", 7),
+        ("a.b", 3),
+    ]:
+        assert parse_text_path(build_text_path(slot_key, idx)) == (slot_key, idx)
+
+
+def test_build_text_path_rejects_empty_slot_key():
+    with pytest.raises(ValueError):
+        build_text_path("", 0)
+
+
+def test_build_text_path_rejects_non_string_slot_key():
+    with pytest.raises(ValueError):
+        build_text_path(123, 0)  # type: ignore[arg-type]
+
+
+def test_build_text_path_rejects_negative_index():
+    with pytest.raises(ValueError):
+        build_text_path("slot", -1)
+
+
+def test_build_text_path_rejects_non_int_index():
+    with pytest.raises(ValueError):
+        build_text_path("slot", "0")  # type: ignore[arg-type]
+
+
+def test_build_text_path_rejects_bool_index():
+    # bool is an int subclass — must still be rejected to avoid silent
+    # path corruption (True → 'slot.1', False → 'slot.0').
+    with pytest.raises(ValueError):
+        build_text_path("slot", True)  # type: ignore[arg-type]
+
+
+# ─── iter_zone_stamps ─────────────────────────────────────────────────────
+
+
+def test_iter_zone_stamps_list_slots():
+    payload = {
+        "body": ["line A", "line B", "line C"],
+    }
+    assert list(iter_zone_stamps(payload)) == [
+        ("body", 0), ("body", 1), ("body", 2),
+    ]
+
+
+def test_iter_zone_stamps_preserves_dict_order():
+    payload = {
+        "row_2": ["x", "y"],
+        "row_1": ["p"],
+        "row_3": ["q", "r"],
+    }
+    assert list(iter_zone_stamps(payload)) == [
+        ("row_2", 0), ("row_2", 1),
+        ("row_1", 0),
+        ("row_3", 0), ("row_3", 1),
+    ]
+
+
+def test_iter_zone_stamps_skips_non_list_values():
+    payload = {
+        "title": "Frame Title",       # scalar — skipped
+        "label": 42,                  # scalar — skipped
+        "lines": ["a", "b"],          # list  — yielded
+        "meta": {"k": "v"},           # mapping — skipped
+    }
+    assert list(iter_zone_stamps(payload)) == [("lines", 0), ("lines", 1)]
+
+
+def test_iter_zone_stamps_skips_empty_or_non_string_keys():
+    payload = {
+        "": ["x"],
+        123: ["y"],          # type: ignore[dict-item]
+        "ok": ["z"],
+    }
+    assert list(iter_zone_stamps(payload)) == [("ok", 0)]
+
+
+def test_iter_zone_stamps_empty_payload():
+    assert list(iter_zone_stamps({})) == []
+
+
+def test_iter_zone_stamps_non_mapping():
+    assert list(iter_zone_stamps(None)) == []  # type: ignore[arg-type]
+    assert list(iter_zone_stamps([])) == []  # type: ignore[arg-type]
+
+
+def test_iter_zone_stamps_empty_list_value():
+    payload = {"lines": []}
+    assert list(iter_zone_stamps(payload)) == []
+
+
+# ─── stamp_zone_html ──────────────────────────────────────────────────────
+
+
+def test_stamp_zone_html_basic_stamping():
+    html = (
+        '<div class="zone">'
+        '<div class="text-line">A</div>'
+        '<div class="text-line">B</div>'
+        '</div>'
+    )
+    out = stamp_zone_html(html, {"body": ["A", "B"]})
+    assert f'<div {TEXT_PATH_ATTR}="body.0" class="text-line">A</div>' in out
+    assert f'<div {TEXT_PATH_ATTR}="body.1" class="text-line">B</div>' in out
+
+
+def test_stamp_zone_html_preserves_modifier_classes():
+    html = (
+        '<div class="text-line text-line--bullet">A</div>'
+        '<div class="text-line text-line--indent-1">B</div>'
+    )
+    out = stamp_zone_html(html, {"body": ["A", "B"]})
+    assert 'class="text-line text-line--bullet"' in out
+    assert 'class="text-line text-line--indent-1"' in out
+    assert f'{TEXT_PATH_ATTR}="body.0"' in out
+    assert f'{TEXT_PATH_ATTR}="body.1"' in out
+
+
+def test_stamp_zone_html_idempotent():
+    html = '<div class="text-line">A</div>'
+    once = stamp_zone_html(html, {"body": ["A"]})
+    twice = stamp_zone_html(once, {"body": ["A"]})
+    assert once == twice
+    # Only one occurrence of the attribute on the tag.
+    assert twice.count(TEXT_PATH_ATTR) == 1
+
+
+def test_stamp_zone_html_excess_text_lines_unstamped():
+    # 3 text-line divs, only 2 stamps available — last div left alone.
+    html = (
+        '<div class="text-line">A</div>'
+        '<div class="text-line">B</div>'
+        '<div class="text-line">C</div>'
+    )
+    out = stamp_zone_html(html, {"body": ["A", "B"]})
+    assert f'{TEXT_PATH_ATTR}="body.0"' in out
+    assert f'{TEXT_PATH_ATTR}="body.1"' in out
+    # The third div remains unstamped (no data-text-path).
+    assert out.count(TEXT_PATH_ATTR) == 2
+
+
+def test_stamp_zone_html_excess_stamps_no_crash():
+    # 1 text-line, 3 stamps available — only the first is consumed.
+    html = '<div class="text-line">A</div>'
+    out = stamp_zone_html(html, {"body": ["A", "B", "C"]})
+    assert f'{TEXT_PATH_ATTR}="body.0"' in out
+    assert f'{TEXT_PATH_ATTR}="body.1"' not in out
+
+
+def test_stamp_zone_html_no_text_lines_no_op():
+    html = '<div class="zone"><span>frame title</span></div>'
+    out = stamp_zone_html(html, {"body": ["A"]})
+    assert out == html
+
+
+def test_stamp_zone_html_empty_payload_no_op():
+    html = '<div class="text-line">A</div>'
+    assert stamp_zone_html(html, {}) == html
+    assert stamp_zone_html(html, []) == html
+
+
+def test_stamp_zone_html_empty_html_no_op():
+    assert stamp_zone_html("", {"body": ["A"]}) == ""
+
+
+def test_stamp_zone_html_non_string_html_no_op():
+    assert stamp_zone_html(None, {"body": ["A"]}) is None  # type: ignore[arg-type]
+
+
+def test_stamp_zone_html_walks_multiple_slots_in_order():
+    # Mirrors the bim_current_problems_paired family template line shape:
+    # multiple slots producing interleaved text-line divs.
+    html = (
+        '<div class="text-line">title-x</div>'      # slot_a.0
+        '<div class="text-line">title-y</div>'      # slot_a.1
+        '<div class="text-line">body-1</div>'       # slot_b.0
+        '<div class="text-line">body-2</div>'       # slot_b.1
+        '<div class="text-line">body-3</div>'       # slot_b.2
+    )
+    payload = {
+        "slot_a": ["title-x", "title-y"],
+        "slot_b": ["body-1", "body-2", "body-3"],
+    }
+    out = stamp_zone_html(html, payload)
+    assert f'{TEXT_PATH_ATTR}="slot_a.0"' in out
+    assert f'{TEXT_PATH_ATTR}="slot_a.1"' in out
+    assert f'{TEXT_PATH_ATTR}="slot_b.0"' in out
+    assert f'{TEXT_PATH_ATTR}="slot_b.1"' in out
+    assert f'{TEXT_PATH_ATTR}="slot_b.2"' in out
+
+
+def test_stamp_zone_html_does_not_match_unrelated_divs():
+    # A div that is NOT a text-line must not be stamped.
+    html = (
+        '<div class="zone">'
+        '<div class="other-class">untouched</div>'
+        '<div class="text-line">A</div>'
+        '</div>'
+    )
+    out = stamp_zone_html(html, {"body": ["A"]})
+    assert 'class="other-class"' in out
+    assert f'{TEXT_PATH_ATTR}="body.0"' in out
+    assert out.count(TEXT_PATH_ATTR) == 1
+
+
+def test_stamp_zone_html_accepts_explicit_stamp_sequence():
+    # When the caller wants to override dict-iteration order (or stamp
+    # a subset), they can pass a list of (slot_key, line_index) tuples.
+    html = (
+        '<div class="text-line">first</div>'
+        '<div class="text-line">second</div>'
+    )
+    stamps = [("custom", 7), ("custom", 9)]
+    out = stamp_zone_html(html, stamps)
+    assert f'{TEXT_PATH_ATTR}="custom.7"' in out
+    assert f'{TEXT_PATH_ATTR}="custom.9"' in out
+
+
+def test_stamp_zone_html_explicit_sequence_drops_malformed():
+    html = '<div class="text-line">A</div>'
+    # Mix valid + malformed: only the valid stamp is consumed.
+    stamps = [("", 0), ("ok", -1), ("ok", "0"), ("ok", 3)]  # type: ignore[list-item]
+    out = stamp_zone_html(html, stamps)  # type: ignore[arg-type]
+    assert f'{TEXT_PATH_ATTR}="ok.3"' in out
+    assert out.count(TEXT_PATH_ATTR) == 1
+
+
+def test_stamp_zone_html_compound_slot_key():
+    # Compound slot keys (with embedded '.') round-trip through stamp +
+    # parse symmetry — the resolver's rpartition split recovers the
+    # original (slot_key, line_index).
+    html = '<div class="text-line">x</div>'
+    out = stamp_zone_html(html, {"a.b.c": ["x"]})
+    assert f'{TEXT_PATH_ATTR}="a.b.c.0"' in out
+    # Spot-check resolver inverse on the emitted path.
+    assert parse_text_path("a.b.c.0") == ("a.b.c", 0)
+
+
+def test_stamp_zone_html_idempotent_when_some_lines_prestamped():
+    # If some text-line elements are already stamped, the prestamped tag
+    # is preserved verbatim AND the stamp counter is NOT advanced for it
+    # (so the next unstamped tag gets the next-in-sequence stamp).
+    html = (
+        f'<div {TEXT_PATH_ATTR}="manual.0" class="text-line">A</div>'
+        '<div class="text-line">B</div>'
+    )
+    out = stamp_zone_html(html, {"body": ["A", "B"]})
+    # First tag preserved as-is (idempotent short-circuit).
+    assert 'manual.0' in out
+    # Second tag consumes the first available stamp ('body.0'); the
+    # prestamped tag does NOT consume from the stamp sequence.
+    assert f'{TEXT_PATH_ATTR}="body.0"' in out
+    # Total occurrences of the attribute = 2 (one manual + one fresh).
+    assert out.count(TEXT_PATH_ATTR) == 2
+
+
+def test_stamp_zone_html_text_line_with_attributes_before_class():
+    # The regex must match text-line opening tags regardless of attribute
+    # ordering — class may not be the first attribute.
+    html = '<div data-foo="x" class="text-line">A</div>'
+    out = stamp_zone_html(html, {"body": ["A"]})
+    assert f'{TEXT_PATH_ATTR}="body.0"' in out
+    assert 'data-foo="x"' in out
+    assert 'class="text-line"' in out

tests/test_user_overrides_io.py

@@ -3,9 +3,13 @@
 Covers the persisted axes called out in the Stage 2 plan
 (IMP-51 #79 u1 extended this to 5 axes by adding ``image_overrides``;
 IMP-45 #74 u1 extended to 6 axes by adding ``slide_css``;
-IMP-55 #93 u1 extended to 7 axes by adding ``manual_section_assignment``):
+IMP-55 #93 u1 extended to 7 axes by adding ``manual_section_assignment``;
+IMP-56 #90 u1 extended to 8 axes by adding ``text_overrides``;
+IMP-56 #90 u2 extended to 9 axes by adding ``structure_overrides`` —
+scope LOCKED to ``{slot_order, hidden_slots}``; frame swap stays on the
+existing ``frames`` axis):
 
-1. Round-trip ``save`` → ``load`` (7 KNOWN_AXES + foreign top-level keys).
+1. Round-trip ``save`` → ``load`` (9 KNOWN_AXES + foreign top-level keys).
 2. Unknown-key passthrough (foreign axes preserved across partial merges).
 3. Missing / corrupt / non-object behavior (graceful ``{}`` + stderr warning).
 4. Invalid keys (``InvalidOverrideKey`` raised on traversal / separators /
@@ -123,25 +127,50 @@ def _full_payload() -> dict:
         },
         "slide_css": "<style>.slide .frame-process-product .label { font-size: 14px; }</style>",
         "manual_section_assignment": True,
+        "text_overrides": {"zone-top": {"slot_title.0": "edited headline"}},
+        "structure_overrides": {
+            "zone-top": {
+                "slot_order": ["slot_title", "slot_body"],
+                "hidden_slots": ["slot_caption"],
+            }
+        },
     }
 
 
 def test_known_axes_includes_image_overrides():
-    """IMP-51 #79 u1 — ``image_overrides`` is a known axis (now 7 total)."""
+    """IMP-51 #79 u1 — ``image_overrides`` is a known axis (now 9 total)."""
     assert "image_overrides" in KNOWN_AXES
-    assert len(KNOWN_AXES) == 7
+    assert len(KNOWN_AXES) == 9
 
 
 def test_known_axes_includes_slide_css():
-    """IMP-45 #74 u1 — ``slide_css`` is a known axis (7 total)."""
+    """IMP-45 #74 u1 — ``slide_css`` is a known axis (9 total)."""
     assert "slide_css" in KNOWN_AXES
-    assert len(KNOWN_AXES) == 7
+    assert len(KNOWN_AXES) == 9
 
 
 def test_known_axes_includes_manual_section_assignment():
-    """IMP-55 #93 u1 — bool intent marker is a known axis (7 total)."""
+    """IMP-55 #93 u1 — bool intent marker is a known axis (9 total)."""
     assert "manual_section_assignment" in KNOWN_AXES
-    assert len(KNOWN_AXES) == 7
+    assert len(KNOWN_AXES) == 9
+
+
+def test_known_axes_includes_text_overrides():
+    """IMP-56 #90 u1 — ``text_overrides`` is a known axis (9 total)."""
+    assert "text_overrides" in KNOWN_AXES
+    assert len(KNOWN_AXES) == 9
+
+
+def test_known_axes_includes_structure_overrides():
+    """IMP-56 #90 u2 — ``structure_overrides`` is a known axis (9 total).
+
+    Scope is locked to ``{slot_order, hidden_slots}`` only; frame swap
+    stays on the existing ``frames`` axis (verified at resolver u6 + Step
+    12 apply u7). The IO layer itself only enforces the axis name + the
+    foreign-key preservation invariant.
+    """
+    assert "structure_overrides" in KNOWN_AXES
+    assert len(KNOWN_AXES) == 9
 
 
 def test_save_then_load_round_trip(tmp_path):
@@ -170,6 +199,8 @@ def test_save_partial_payload_preserves_other_axes(tmp_path):
     assert loaded["image_overrides"] == _full_payload()["image_overrides"]
     assert loaded["slide_css"] == _full_payload()["slide_css"]
     assert loaded["manual_section_assignment"] is True
+    assert loaded["text_overrides"] == _full_payload()["text_overrides"]
+    assert loaded["structure_overrides"] == _full_payload()["structure_overrides"]
 
 
 def test_save_partial_image_overrides_preserves_other_axes(tmp_path):
@@ -193,6 +224,8 @@ def test_save_partial_image_overrides_preserves_other_axes(tmp_path):
     assert loaded["frames"] == _full_payload()["frames"]
     assert loaded["slide_css"] == _full_payload()["slide_css"]
     assert loaded["manual_section_assignment"] is True
+    assert loaded["text_overrides"] == _full_payload()["text_overrides"]
+    assert loaded["structure_overrides"] == _full_payload()["structure_overrides"]
 
 
 def test_save_axis_replaces_not_deep_merges(tmp_path):
@@ -265,12 +298,15 @@ def test_save_writes_pretty_sorted_json_for_diffability(tmp_path):
     key = "03"
     save(key, _full_payload(), root=tmp_path)
     raw = (tmp_path / "03.json").read_text(encoding="utf-8")
-    # sort_keys=True → KNOWN_AXES come out alphabetically
+    # sort_keys=True → KNOWN_AXES come out alphabetically. ``structure_overrides``
+    # (IMP-56 #90 u2) sorts between ``slide_css`` and ``text_overrides``.
     pos_frames = raw.index('"frames"')
     pos_image_overrides = raw.index('"image_overrides"')
     pos_layout = raw.index('"layout"')
     pos_manual = raw.index('"manual_section_assignment"')
     pos_slide_css = raw.index('"slide_css"')
+    pos_structure_overrides = raw.index('"structure_overrides"')
+    pos_text_overrides = raw.index('"text_overrides"')
     pos_zg = raw.index('"zone_geometries"')
     pos_zs = raw.index('"zone_sections"')
     assert (
@@ -279,6 +315,8 @@ def test_save_writes_pretty_sorted_json_for_diffability(tmp_path):
         < pos_layout
         < pos_manual
         < pos_slide_css
+        < pos_structure_overrides
+        < pos_text_overrides
         < pos_zg
         < pos_zs
     )

tests/test_user_overrides_pipeline_fallback.py

@@ -55,6 +55,13 @@ def _exec_main_block(
         # the section-assignment axis; the new kwargs are captured here so any
         # follow-up test can pin them without re-touching this harness.
         override_slide_css=None,
+        # IMP-56 (#90) u16 — absorb the two new file-only axes added to
+        # ``run_phase_z2_mvp1`` so the existing harness keeps working when
+        # the CLI dispatch passes the new kwargs through. Both default to
+        # ``None`` so the no-file / corrupt-file / invalid-stem tests can
+        # continue asserting "all overrides None".
+        override_text_overrides=None,
+        override_structure_overrides=None,
         reuse_from=None,
     ):
         captured["mdx_path"] = mdx_path
@@ -65,6 +72,8 @@ def _exec_main_block(
         captured["override_section_assignments"] = override_section_assignments
         captured["override_image_overrides"] = override_image_overrides
         captured["override_slide_css"] = override_slide_css
+        captured["override_text_overrides"] = override_text_overrides
+        captured["override_structure_overrides"] = override_structure_overrides
         captured["reuse_from"] = reuse_from
 
     monkeypatch.setattr(_pz2, "run_phase_z2_mvp1", _fake_run)
@@ -600,3 +609,69 @@ def test_cli_section_assignment_works_without_persisted_file(
     )
 
     assert captured["override_section_assignments"] == {"top": ["cli-only"]}
+
+
+# -- 6. IMP-56 (#90) u16 — text_overrides + structure_overrides file fallback
+
+
+def test_file_text_overrides_flow_through_when_no_cli(tmp_path, monkeypatch):
+    """text_overrides axis is file-only — JSON payload reaches run kwarg."""
+    _redirect_overrides_root(tmp_path, monkeypatch)
+    (tmp_path / "03.json").write_text(
+        json.dumps({
+            "text_overrides": {
+                "top": {"title.0": "edited title", "body.1": "edited line"},
+                "bottom_l": {"caption.0": "edited caption"},
+            },
+        }),
+        encoding="utf-8",
+    )
+
+    captured: dict[str, Any] = {}
+    _exec_main_block(
+        captured, ["src.phase_z2_pipeline", "03.mdx"], monkeypatch,
+    )
+
+    assert captured["override_text_overrides"] == {
+        "top": {"title.0": "edited title", "body.1": "edited line"},
+        "bottom_l": {"caption.0": "edited caption"},
+    }
+    # No structure payload on file → kwarg collapses to None via ``or None``.
+    assert captured["override_structure_overrides"] is None
+
+
+def test_file_structure_overrides_flow_through_when_no_cli(
+    tmp_path, monkeypatch
+):
+    """structure_overrides axis is file-only; inner keys locked to
+    slot_order + hidden_slots (any other inner key is dropped by the
+    CLI gate). Non-string list elements are dropped too."""
+    _redirect_overrides_root(tmp_path, monkeypatch)
+    (tmp_path / "03.json").write_text(
+        json.dumps({
+            "structure_overrides": {
+                "top": {
+                    "slot_order": ["c", "a", "b"],
+                    "hidden_slots": ["d"],
+                    # foreign key — must be dropped by the CLI gate
+                    "frame_id": "swap_attempt",
+                    # non-string elements — must be dropped per-entry
+                    "slot_order_with_junk": ["x", 1, None, "y"],
+                },
+                "bottom": {"hidden_slots": ["e"]},
+            },
+        }),
+        encoding="utf-8",
+    )
+
+    captured: dict[str, Any] = {}
+    _exec_main_block(
+        captured, ["src.phase_z2_pipeline", "03.mdx"], monkeypatch,
+    )
+
+    assert captured["override_structure_overrides"] == {
+        "top": {"slot_order": ["c", "a", "b"], "hidden_slots": ["d"]},
+        "bottom": {"hidden_slots": ["e"]},
+    }
+    # No text payload on file → kwarg collapses to None.
+    assert captured["override_text_overrides"] is None