feat(#79): IMP-51 image_overrides axis (u1~u11 backend stamp+CLI+CSS inject + frontend drag/resize+persistence + tests)

Front/client/src/pages/Home.tsx

@@ -15,6 +15,7 @@ import {
   getSelectedRegion,
   moveSectionToZone,
   saveZoneSizes,
+  saveImageOverride,
   deriveUserOverridesKey,
   applyPersistedNonFrameOverrides,
   remapPersistedFramesToZoneFrames,
@@ -540,6 +541,37 @@ export default function Home() {
     setHasPendingChanges(true);
   }, []);
 
+  // IMP-51 (#79) u10 — wire SlideCanvas's user-content image drag/resize
+  // emit into the 5th persisted axis. Mirrors handleZoneResize exactly:
+  //   • merge the single (imageId → {x,y,w,h}) tick onto the prior
+  //     in-memory `image_overrides` map via the u11 `saveImageOverride`
+  //     helper so the immutable update path is shared with the test suite,
+  //   • forward the full merged snapshot through `saveUserOverrides`
+  //     (the u3 typed client) under the `image_overrides` key — the 300ms
+  //     debounce defined alongside `zone_geometries` collapses the
+  //     per-mousemove emits into one PUT at gesture-end,
+  //   • flip `hasPendingChanges` so the "선택대로 재생성하기" CTA appears.
+  // Coordinates are slide-absolute percent (0–100) from u8/u9 — passed
+  // through unchanged so the on-disk schema matches the SlideCanvas
+  // overlay, the stamper selector (u4), and the render-time CSS
+  // injector (u7) without any per-zone transform.
+  const handleImageResize = useCallback(
+    (imageId: string, geometry: { x: number; y: number; w: number; h: number }) => {
+      setState((p) => {
+        const nextSelection = saveImageOverride(p.userSelection, imageId, geometry);
+        if (p.uploadedFile) {
+          const key = deriveUserOverridesKey(p.uploadedFile.name);
+          void saveUserOverrides(key, {
+            image_overrides: nextSelection.overrides.image_overrides,
+          });
+        }
+        return { ...p, userSelection: nextSelection };
+      });
+      setHasPendingChanges(true);
+    },
+    [],
+  );
+
   // 편집 모드 텍스트 변경 시 hasPendingChanges 활성. useCallback 으로 reference 안정화 —
   // SlideCanvas 의 useEffect 가 매번 rerun 안 하도록 (resize drag 매 mousemove 마다
   // re-render 시 useEffect retrigger → iframe contentEditable 재설정 = 매우 느림).
@@ -745,6 +777,8 @@ export default function Home() {
             onSectionDrop={handleSectionDrop}
             onLayoutResize={handleLayoutResize}
             onZoneResize={handleZoneResize}
+            imageOverrides={state.userSelection.overrides.image_overrides}
+            onImageResize={handleImageResize}
           />
         </main>