fix(bearing): C4 and C5 are the 교각축 distances from the bearing to the block edges (승인 2026-10-26)

- bearingEdgeDistances measures along the 교각축: 분리 600 / 600; 일체 from the
  pair block centred on the mean 교각축 position (P1 outer margins 557).
- Table headings updated; C1 · C2 · C3 on the plan are measured on the 교축 from the drawn positions.

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

src/view/bearing-plan-svg.ts

@@ -79,9 +79,10 @@ export function bearingPlanSvg(m: PierModel, pairIndex: number, overlay?: Bearin
     `<line x1="${x1}" y1="${y}" x2="${x2}" y2="${y}" stroke="#55606E" stroke-width="6"></line><line x1="${x1}" y1="${y - 50}" x2="${x1}" y2="${y + 50}" stroke="#55606E" stroke-width="6"></line><line x1="${x2}" y1="${y - 50}" x2="${x2}" y2="${y + 50}" stroke="#55606E" stroke-width="6"></line><text x="${(x1 + x2) / 2}" y="${y + 110}" text-anchor="middle" font-size="90" fill="#18212B">${label}</text>`;
   const y1 = 760;
   const y2 = 1000;
-  parts.push(dimLine(xLeft, X(f.n), y1, `C1 ${Math.round(d(f.no).leftMm ?? 600)}`));
+  // C1 and C2 are along the 교축 (horizontal), measured on the drawn positions.
+  parts.push(dimLine(xLeft, X(f.n), y1, `C1 ${Math.round(X(f.n) - xLeft)}`));
   parts.push(dimLine(X(f.n), X(k.n), y1, `C2 ${Math.round(Math.abs(k.n - f.n) * 1000)}`));
-  parts.push(dimLine(X(k.n), xRight, y1, `C1 ${Math.round(d(k.no).rightMm ?? 600)}`));
+  parts.push(dimLine(X(k.n), xRight, y1, `C1 ${Math.round(xRight - X(k.n))}`));
   parts.push(dimLine(xLeft, xRight, y2, `C3 ${Math.round((xRight - xLeft))}`));
 
   // C4 and C5 as in the 시안: vertical dimensions on the left of the blocks, from the top edge to the bearing row (C4) and
@@ -90,8 +91,8 @@ export function bearingPlanSvg(m: PierModel, pairIndex: number, overlay?: Bearin
   const halfDepth = 600;
   const vdim = (y1: number, y2: number, label: string) =>
     `<line x1="${xv}" y1="${y1}" x2="${xv}" y2="${y2}" stroke="#55606E" stroke-width="6"></line><line x1="${xv - 50}" y1="${y1}" x2="${xv + 50}" y2="${y1}" stroke="#55606E" stroke-width="6"></line><line x1="${xv - 50}" y1="${y2}" x2="${xv + 50}" y2="${y2}" stroke="#55606E" stroke-width="6"></line><text x="${xv - 90}" y="${(y1 + y2) / 2 + 30}" text-anchor="end" font-size="90" fill="#18212B">${label}</text>`;
-  parts.push(vdim(-halfDepth, 0, `C4 ${Math.round(d(f.no).leftMm ?? 0)}`));
-  parts.push(vdim(0, halfDepth, `C5 ${Math.round(d(k.no).rightMm ?? 0)}`));
+  parts.push(vdim(-halfDepth, 0, `C4 ${Math.round(d(f.no).leftMm)}`));
+  parts.push(vdim(0, halfDepth, `C5 ${Math.round(d(k.no).rightMm)}`));
 
   return `<svg viewBox="-1900 -1300 3800 2600" width="100%" style="max-width: 560px; height: auto" role="img" aria-label="교량받침 상세 평면: 쌍 ${pair.frontNo}·${pair.backNo}, 블록 한 줄, 교축·교각축 방향, C1·C2·C3, C4·C5, 도면값 겹쳐 보기">${parts.join('')}</svg>`;
 }