fix(rebar): 확대기초 철근 — 구간별 3D 위치, 기둥 소속, 길이별 행, 2조각 수량

- 3D: 확대기초 철근을 늘 구간 0에 그려, 꺾인 교각의 구간 1 기초(산외교 P11 ③)는 철근이 없고 구간 0 기초에 겹쳐 그려졌다
- 기초에 속한 기둥을 같은 구간 안에서만 찾는다 (B9 기둥 구역이 다른 구간 기둥으로 잘못 빠지던 것)
- 길이가 다른 기초의 철근을 가장 긴 길이 하나로 합치지 않고 길이별 조각으로 둔다
- 정척 초과 2조각 이음 행이 철근 한 개당 한 조각만 중량에 넣던 것을 두 조각으로 (P1 B6 31개 → 62조각)

Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>

src/core/rebar/summary.ts

@@ -391,27 +391,34 @@ export function rebarSummary(
   if (model.footings.length > 0) {
     // Each footing (분리 or 일체) gives the same bar set. Several footings add their counts per bar name;
     // the length is the longest of them (the largest footing governs the bar).
-    const agg = new Map<string, FootingBar>();
+    // Per footing (2026-11-10): the columns of its own stretch only, and every bar length kept (a bent pier has footings
+    // of different lengths; the longest no longer stands for all).
+    const byName = new Map<string, { first: FootingBar; lengths: Map<number, number> }>();
     for (const f of model.footings) {
       // Columns on this footing, as x mm from the footing centre (for the B9 column-zone rule).
-      const columnX = model.columns.filter((c) => Math.abs(c.s - f.s) <= f.length / 2).map((c) => (c.s - f.s) * 1000);
+      const columnX = model.columns.filter((c) => c.k === f.k && Math.abs(c.s - f.s) <= f.length / 2).map((c) => (c.s - f.s) * 1000);
       for (const b of footingBarList(f.length * 1000, f.width * 1000, (f.top - f.bottom) * 1000, columnX, model.footingRebar)) {
-        const cur = agg.get(b.name);
-        if (cur) {
-          cur.count += b.count;
-          cur.length = Math.max(cur.length, b.length);
-        } else {
-          agg.set(b.name, { ...b });
-        }
+        const cur = byName.get(b.name) ?? { first: b, lengths: new Map<number, number>() };
+        cur.lengths.set(b.length, (cur.lengths.get(b.length) ?? 0) + b.count);
+        byName.set(b.name, cur);
       }
     }
-    for (const b of agg.values()) {
-      const split = splitPieces(b.length, 25.4, fyOf(mFooting, b.size), mFooting.fck, STANDARD_BAR);
-      if (split && b.length > STANDARD_BAR && b.name !== 'B9') {
-        rows.push({ member: 'footing', name: b.name, size: b.size, count: b.count, length: split.pieceLength, note: `${b.note}, 2조각 이음 (추천안, 겹침 ${Math.round(split.lap)})` });
-        warnings.push({ code: 'RB-F08', message: `${b.name} 길이 ${Math.round(b.length)} mm > 정척 ${STANDARD_BAR} mm: 2조각 이음을 추천안으로 적용 (Q-B6).`, target: 'footing', bar: b.name });
+    for (const { first: b, lengths } of byName.values()) {
+      // Over 정척: two pieces lapped (추천안, Q-B6); both pieces count (the row used to weigh only one per bar).
+      const pieces: { length: number; count: number }[] = [];
+      let lap: number | null = null;
+      for (const [length, count] of lengths) {
+        const split = b.name === 'B9' ? null : splitPieces(length, 25.4, fyOf(mFooting, b.size), mFooting.fck, STANDARD_BAR);
+        if (split) { pieces.push({ length: split.pieceLength, count: 2 * count }); lap = split.lap; } else pieces.push({ length, count });
+      }
+      const count = [...lengths.values()].reduce((sum, n) => sum + n, 0);
+      const longest = Math.max(...lengths.keys());
+      if (lap !== null) {
+        rows.push({ member: 'footing', name: b.name, size: b.size, count, length: pieces.length === 1 ? pieces[0].length : null, pieces,
+          note: `${b.note}, 2조각 이음 (추천안, 겹침 ${Math.round(lap)})` });
+        warnings.push({ code: 'RB-F08', message: `${b.name} 길이 ${Math.round(longest)} mm > 정척 ${STANDARD_BAR} mm: 2조각 이음을 추천안으로 적용 (Q-B6).`, target: 'footing', bar: b.name });
       } else {
-        rows.push({ member: 'footing', name: b.name, size: b.size, count: b.count, length: b.length, note: b.note });
+        rows.push({ member: 'footing', name: b.name, size: b.size, count, length: pieces.length === 1 ? pieces[0].length : null, ...(pieces.length > 1 ? { pieces } : {}), note: b.note });
       }
     }
   } else {