feat(rebar): 확대기초 철근표 간격·실간격을 격자 실간격 s와 s_v에 연동

- B1–B8: 간격 2s, 실간격 s (cycle 2·4·6·8), 실간격 2s (B1·B3·B5·B7)
- B9: 간격 4s, 실간격 2s (엇갈림) · B11·B12: 간격 4s
- B10-1·B10-2: 간격·실간격 = s_v
- 근거: s 또는 s_v가 기본값과 다르면 '입력', 같으면 '기본값'

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

tests/footing-rebar-settings.test.ts

@@ -29,6 +29,21 @@ describe('확대기초 배근 입력 (승인 2026-10-26, 시안 ③ 확대기초
     expect(b4.count).not.toBe(b4Default.count);
   });
 
+  it('철근표 간격: P1 기본값 B2 250 / 125 · B10-1 200 (기본값); s 150 → B2 300 / 150 · B1 300 (입력)', () => {
+    const base = rebarSummary(buildPier(loadP1())).rows;
+    const b2 = base.find((r) => r.name === 'B2')!;
+    expect([b2.spacing, b2.actual, b2.basis]).toEqual(['250', '125', 'default']);
+    const b10 = base.find((r) => r.name === 'B10-1')!;
+    expect([b10.spacing, b10.basis]).toEqual(['200', 'default']);
+
+    const rows = rebarSummary(buildPier({ ...loadP1(), footingRebar: { s: 150 } })).rows;
+    const b2s = rows.find((r) => r.name === 'B2')!;
+    expect([b2s.spacing, b2s.actual, b2s.basis]).toEqual(['300', '150', 'input']);
+    const b1s = rows.find((r) => r.name === 'B1')!;
+    expect([b1s.spacing, b1s.actual]).toEqual(['300', '300']);
+    expect(rows.find((r) => r.name === 'B10-1')!.basis).toBe('default');
+  });
+
   it('the 조립 단 배수 n reaches the assembly levels', () => {
     const H = 2000;
     const base = assemblyJs(H, DEFAULT_FOOTING_REBAR);