feat(core): parse P1 workbook and build T-type pier shape

- parse Excel input by header strings (pier, IP, bearing tables)
- DMS azimuth parser (E03), input validation (E01, E02)
- pure geometry: axis, bearings, stepped coping, column, footing, piles, blinding
- warnings W01, W02, W05, W07, I01
- regression tests against spec.md section 12 (P1)

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

src/core/validate.ts

@@ -0,0 +1,69 @@
+import { DIM, type PierModel } from './geometry';
+import type { Issue, PierInput, PierType } from './types';
+
+const EXPECTED_COLUMNS: Record<PierType, number> = { 'T형': 1, '2주형': 2, '3주형': 3 };
+
+/** Rules from spec §10 that are not implemented in this stage. Shown to the user, never silently skipped. */
+export const NOT_IMPLEMENTED_RULES = [
+  'E04 fck 미입력 (배근 단계, 3단계)',
+  'W03 받침 중심 ~ 계단 경계 < 블럭 폭/2',
+  'W04 블럭이 코핑 평면 밖',
+  'W06 속성 복사 건너뜀 (2단계)',
+  'W08 솔플레이트 T1−T2 검사 (2단계)',
+  '다주형 코핑 헌치·Level−300 (Q3), 일체기초 판정 (2·3주형)',
+] as const;
+
+/** Input-level checks (spec §10 E01, E02). Returns false when the pier must not be built. */
+export function validateInput(input: PierInput, issues: Issue[]): boolean {
+  let ok = true;
+  if (input.columnCount !== EXPECTED_COLUMNS[input.type]) {
+    issues.push({
+      code: 'E01',
+      level: 'E',
+      pier: input.name,
+      message: `교각형식 ${input.type}과 기둥갯수 ${input.columnCount}개가 맞지 않습니다. 기둥 ${EXPECTED_COLUMNS[input.type]}개로 맞추세요.`,
+    });
+    ok = false;
+  }
+  const front = input.bearings.filter((b) => b.row === '전열').length;
+  const back = input.bearings.filter((b) => b.row === '후열').length;
+  if (front !== back) {
+    issues.push({ code: 'E02', level: 'E', pier: input.name, message: `전열 받침 ${front}개, 후열 받침 ${back}개로 수가 다릅니다.` });
+    ok = false;
+  }
+  return ok;
+}
+
+/** Geometry-level checks (spec §10 W01, W02, W05, W07, I01) on a built model. */
+export function validatePier(input: PierInput, model: PierModel, issues: Issue[]): void {
+  const ip2Gap = Math.hypot(model.ip2Input.e - model.ip2Calc.e, model.ip2Input.n - model.ip2Calc.n);
+  if (ip2Gap > 0.001) {
+    issues.push({
+      code: 'W01',
+      level: 'W',
+      pier: input.name,
+      message: `IP2 입력과 재계산값이 ${(ip2Gap * 1000).toFixed(1)} mm 다릅니다. 재계산값을 사용합니다.`,
+    });
+  }
+  const minBlock = Math.min(model.derived.blockHeightFront, model.derived.blockHeightBack);
+  if (minBlock <= 0) {
+    issues.push({ code: 'W02', level: 'W', pier: input.name, message: '받침블럭 콘크리트 높이가 0 이하입니다. 블럭을 생략합니다.' });
+  }
+  if (input.foundationType !== '현장타설말뚝' && model.footings.some((f) => f.top > input.groundEl)) {
+    issues.push({ code: 'W05', level: 'W', pier: input.name, message: '확대기초 상면이 지반고보다 높습니다.' });
+  }
+  if (model.derived.frontBackDiffSpread > DIM.lateralTolerance) {
+    issues.push({ code: 'W07', level: 'I', pier: input.name, message: '전열·후열 EL 차이가 받침마다 다릅니다 (정보).' });
+  }
+  // I01: block concrete below cover + bar diameter (cover 100 mm, S1·S2 H19 from spec §6.3).
+  const cover = 0.1;
+  const barDia = 0.019;
+  if (minBlock < cover + barDia) {
+    issues.push({
+      code: 'I01',
+      level: 'I',
+      pier: input.name,
+      message: `받침블럭 높이 ${(minBlock * 1000).toFixed(0)} mm가 피복 + 철근 지름(${((cover + barDia) * 1000).toFixed(0)} mm)보다 작습니다. 블럭 철근은 코핑 안에 묻힙니다.`,
+    });
+  }
+}