feat(bearing): 일체 choice gated by the pair eccentricity rule (승인 2026-10-26)

- PierInput.bearingLayout: 분리 (default) or 일체, tracked for changes.
- 일체 is selectable only when there is at least one pair and every pair is
  within 100 mm; otherwise the chip is disabled with the reason.
- Validation: B01 (info) when 일체 is chosen and allowed, the block shape is
  still the 분리 shape; B02 (warning) when it is not allowed and the model
  falls back to 분리.
- The 일체 block shape (2500 × 1200) is not modelled yet.

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

tests/bearing-layout.test.ts

@@ -1,6 +1,8 @@
 import { describe, expect, it } from 'vitest';
 import { buildPier, type BlockModel } from '../src/core/geometry';
-import { bearingEdgeDistances, PAIR_ECCENTRICITY_LIMIT_MM, pairEccentricities } from '../src/core/bearing-layout';
+import { bearingEdgeDistances, integratedCheck, PAIR_ECCENTRICITY_LIMIT_MM, pairEccentricities } from '../src/core/bearing-layout';
+import { validatePier } from '../src/core/validate';
+import type { Issue } from '../src/core/types';
 import { loadP1 } from './helpers';
 
 const model = buildPier(loadP1());
@@ -46,3 +48,30 @@ describe('받침 배치 규칙 (승인 2026-10-26)', () => {
     expect(pairEccentricities([block(1, '전열', 1), block(2, '전열', 3), block(6, '후열', 1.05)])).toHaveLength(1);
   });
 });
+
+describe('일체 배치 선택 (승인 2026-10-26)', () => {
+  it('P1 allows 일체 because every pair is within 100 mm', () => {
+    expect(integratedCheck(model.blocks)).toEqual({ allowed: true, overLimit: [] });
+  });
+
+  it('one pair over the limit blocks 일체 and lists that pair', () => {
+    const r = integratedCheck([block(1, '전열', 1.0), block(1, '후열', 1.12)]);
+    expect(r.allowed).toBe(false);
+    expect(r.overLimit.map((p) => p.frontNo)).toEqual([1]);
+  });
+
+  it('no pairs at all does not allow 일체', () => {
+    expect(integratedCheck([]).allowed).toBe(false);
+  });
+
+  it('the model keeps 분리 for now and says so (B01); a 일체 that is not allowed is refused with B02', () => {
+    const input = loadP1();
+    const ok: Issue[] = [];
+    validatePier({ ...input, bearingLayout: '일체' }, model, ok);
+    expect(ok.map((i) => i.code)).toContain('B01');
+    const bad: Issue[] = [];
+    const fake = { ...model, blocks: [block(1, '전열', 1.0), block(1, '후열', 1.12)] } as unknown as typeof model;
+    validatePier({ ...input, bearingLayout: '일체' }, fake, bad);
+    expect(bad.map((i) => i.code)).toContain('B02');
+  });
+});