feat(IMP-16): Step 14 table_self_overflow detection

Add table self-overflow detection with element-identity wrapper dedup,
mirroring the image_aspect_mismatch axis pattern (#45).

JS layer: TABLE_SCROLL_TOL_PX=5 module constant; clippedWrapperMap
built as Map<Element,int> keyed by DOM node reference (NOT className)
so two wrappers with identical class strings remain distinguishable;
table_events collected via querySelectorAll('table').forEach with
closest()-ancestor walk resolving wrapper_clipped_index = int|null.

Py layer: aggregate result['table_events'] and append fail_reason
'table_self_overflow' only when (excess_x>TOL OR excess_y>TOL)
AND wrapper_clipped_index is None; wrapper-clipped path continues
to fail via existing clipped_inner reporting.

Tests (Selenium, chromedriver guard mirrored from image_check):
- Fixture D: standalone <table> overflow → table_self_overflow fail
- Fixture E: <table> in clipped wrapper → dedup suppresses table fail
- Fixture F (F1 acceptance): two wrappers with identical className
  f13b-cell, W1 clipped by non-table child, W2 hosts self-overflow
  <table> with W2 itself NOT clipped → element-identity ensures W2's
  table is not suppressed by W1's class; both fails emitted.

Out of scope: image_events behavior (intact from #45), classifier
pass/fail consumer (→실행-3), debug.json surfacing (→실행-4).

Refs: #46

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/phase_z2_pipeline.py

@@ -133,6 +133,11 @@ DEFAULT_ZONE_MIN_HEIGHT_PX = 100
 # Spec doc row (PHASE-Z-FIT-CLASSIFIER-ROUTER-SPEC) update deferred to IMP-15 실행-4.
 IMAGE_ASPECT_DELTA_TOL = 0.05
 
+# Step 14 table_self_overflow tolerance — scrollW−clientW or scrollH−clientH > TOL ⇒ fail.
+# Local anchor : IMP-15 실행-2 (Gitea issue #46) — table axis acceptance criteria.
+# Mirrors existing inline 5px tolerance used by slide/zone/clipped scans in run_overflow_check.
+TABLE_SCROLL_TOL_PX = 5
+
 # content_weight 계산 가중치
 CONTENT_WEIGHT_COEFFS = {
     "text_per_chars": 800,    # text_len / 800 = score
@@ -2131,6 +2136,14 @@ def run_overflow_check(html_path: Path) -> dict:
 
             const zones = [];
             const zone_geometries_px = [];
+
+            // IMP-15 실행-2 (issue #46) — element-identity dedup map for table_events.
+            // Map<Element, integer> keyed by DOM node reference (NOT class string) so that
+            // two wrappers sharing identical className resolve to distinct map entries.
+            // Populated alongside the existing per-zone clipped_inner scan below.
+            const clippedWrapperMap = new Map();
+            let clippedIdxCounter = 0;
+
             slide.querySelectorAll('.zone').forEach((z) => {
                 const pos = z.getAttribute('data-zone-position') || 'unknown';
                 const tid = z.getAttribute('data-template-id') || '?';
@@ -2178,6 +2191,13 @@ def run_overflow_check(html_path: Path) -> dict:
                             scrollWidth: el.scrollWidth,
                             scrollHeight: el.scrollHeight,
                         });
+                        // IMP-15 실행-2 (issue #46) — element-identity registration.
+                        // Key by DOM node `el`, NOT className: two wrappers with identical
+                        // class string still hash to distinct Map entries.
+                        if (!clippedWrapperMap.has(el)) {
+                            clippedWrapperMap.set(el, clippedIdxCounter);
+                            clippedIdxCounter++;
+                        }
                     }
                 });
                 m.clipped_inner = clipped;
@@ -2259,7 +2279,52 @@ def run_overflow_check(html_path: Path) -> dict:
                 });
             });
 
-            return { slide: slideM, slide_body: bodyM, zones, frame_slot_metrics, zone_geometries_px, image_events };
+            // IMP-15 실행-2 (issue #46) — table_events[] for table_self_overflow detection.
+            // One entry per <table> under .slide. wrapper_clipped_index is the integer index
+            // (from clippedWrapperMap) of the nearest ancestor that is itself in the clipped
+            // wrapper set, or null. Element-identity walk (NOT className) so that two same-class
+            // wrappers (W1 clipped, W2 not) resolve independently for any contained <table>.
+            const table_events = [];
+            slide.querySelectorAll('table').forEach((tbl) => {
+                const parentZone = tbl.closest('.zone');
+                const zonePos = parentZone
+                    ? (parentZone.getAttribute('data-zone-position') || 'unknown')
+                    : 'unknown';
+                const zoneTid = parentZone
+                    ? (parentZone.getAttribute('data-template-id') || '?')
+                    : '?';
+                let wrapper_clipped_index = null;
+                let node = tbl.parentElement;
+                while (node && node !== slide) {
+                    if (clippedWrapperMap.has(node)) {
+                        wrapper_clipped_index = clippedWrapperMap.get(node);
+                        break;
+                    }
+                    node = node.parentElement;
+                }
+                const tblRect = tbl.getBoundingClientRect();
+                const dx = tbl.scrollWidth - tbl.clientWidth;
+                const dy = tbl.scrollHeight - tbl.clientHeight;
+                table_events.push({
+                    zone_position: zonePos,
+                    zone_template_id: zoneTid,
+                    clientWidth: tbl.clientWidth,
+                    clientHeight: tbl.clientHeight,
+                    scrollWidth: tbl.scrollWidth,
+                    scrollHeight: tbl.scrollHeight,
+                    excess_x: Math.max(0, dx),
+                    excess_y: Math.max(0, dy),
+                    wrapper_clipped_index: wrapper_clipped_index,
+                    bbox: {
+                        x: Math.round(tblRect.left - slideRect.left),
+                        y: Math.round(tblRect.top - slideRect.top),
+                        w: Math.round(tblRect.width),
+                        h: Math.round(tblRect.height),
+                    },
+                });
+            });
+
+            return { slide: slideM, slide_body: bodyM, zones, frame_slot_metrics, zone_geometries_px, image_events, table_events };
         """)
 
         screenshot_path = html_path.parent / "preview.png"
@@ -2318,6 +2383,27 @@ def run_overflow_check(html_path: Path) -> dict:
                 f"(template={tid}, tol={IMAGE_ASPECT_DELTA_TOL}, src={src})"
             )
 
+    # IMP-15 실행-2 (issue #46) — table_self_overflow aggregation.
+    # Emit fail_reason only when (excess_x>TOL OR excess_y>TOL) AND wrapper_clipped_index is None.
+    # The clipped-wrapper case is already accounted for by the clipped_inner fail_reason above;
+    # element-identity dedup (clippedWrapperMap keyed by DOM node ref, NOT className) prevents
+    # double-counting and—critically—prevents two same-class wrappers from masking each other.
+    for ev in result.get("table_events", []):
+        if ev.get("wrapper_clipped_index") is not None:
+            continue
+        excess_x = ev.get("excess_x", 0) or 0
+        excess_y = ev.get("excess_y", 0) or 0
+        if excess_x > TABLE_SCROLL_TOL_PX or excess_y > TABLE_SCROLL_TOL_PX:
+            pos = ev.get("zone_position", "unknown")
+            tid = ev.get("zone_template_id", "?")
+            fail_reasons.append(
+                f"table self-overflow in zone--{pos}: "
+                f"excess {excess_y}px vert / {excess_x}px horiz "
+                f"(content {ev.get('scrollWidth')}x{ev.get('scrollHeight')} vs "
+                f"container {ev.get('clientWidth')}x{ev.get('clientHeight')}, "
+                f"template={tid}, tol={TABLE_SCROLL_TOL_PX})"
+            )
+
     result["passed"] = len(fail_reasons) == 0
     result["fail_reasons"] = fail_reasons
     return result