feat(rebar): 코핑 배근 입력 12개 · CP01·CP02 검사 · 적용 버튼

- core/rebar/coping-settings.ts: 입력 정의, 기본값(코핑철근.md), 범위(코핑_입력범위_제안.md), 검사 함수
- 다리 수는 4·6·8 목록으로 두고 홀수는 CP02로 막음
- 값은 적용 버튼을 누를 때만 draft에 쓰고 다시 생성 (범위 밖이면 반영하지 않음)
- PierInput.copingRebar, 모델 copingRebar, 변경 추적 키 추가

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

src/core/rebar/coping-settings.ts

@@ -0,0 +1,86 @@
+/**
+ * 코핑 배근 입력 (승인 2026-10-26, 제안 = RAG/코핑_입력범위_제안.md). The 12 numbers of the ③ 코핑 배근 입력 panel.
+ * Defaults are the 코핑철근.md values; the ranges are the proposal's, pending the design-standard check.
+ */
+export interface CopingRebarSettings {
+  /** 피복 (철근 중심, mm). */
+  cover: number;
+  /** 주철근 기본간격 (mm). */
+  mainSpacing: number;
+  /** 주철근 끝단 최소 여유 (mm). */
+  mainEndGap: number;
+  /** 상면 주철근 단 간격 (mm). */
+  mainLayerGap: number;
+  /** 첫 전단철근 최소 여유 (피복 다음, mm). */
+  firstShearGap: number;
+  /** 전단철근 다리 수 (짝수). */
+  shearLegs: number;
+  /** 전단철근 간격 · 경사 (mm). */
+  spacingS: number;
+  /** 전단철근 간격 · Level (mm). */
+  spacingL: number;
+  /** 측면 수평 간격 (mm). */
+  sideSpacing: number;
+  /** 측면 위 끝 아래 최소 여유 (mm). */
+  sideEndGap: number;
+  /** C14 간격 위 2줄 (mm). */
+  c14UpperSpacing: number;
+  /** C14 간격 아래 줄 (mm). */
+  c14LowerSpacing: number;
+}
+
+export const DEFAULT_COPING_REBAR: CopingRebarSettings = {
+  cover: 100,
+  mainSpacing: 125,
+  mainEndGap: 80,
+  mainLayerGap: 57.2,
+  firstShearGap: 200,
+  shearLegs: 6,
+  spacingS: 250,
+  spacingL: 300,
+  sideSpacing: 250,
+  sideEndGap: 400,
+  c14UpperSpacing: 1000,
+  c14LowerSpacing: 2000,
+};
+
+/** Allowed range per input (inclusive, mm). The shear legs are checked for evenness separately (CP02). */
+export const COPING_REBAR_RANGES: Record<keyof CopingRebarSettings, [number, number]> = {
+  cover: [80, 150],
+  mainSpacing: [100, 150],
+  mainEndGap: [60, 100],
+  mainLayerGap: [50, 70],
+  firstShearGap: [100, 300],
+  shearLegs: [4, 8],
+  spacingS: [200, 350],
+  spacingL: [200, 350],
+  sideSpacing: [200, 300],
+  sideEndGap: [300, 500],
+  c14UpperSpacing: [800, 1200],
+  c14LowerSpacing: [1500, 2500],
+};
+
+export interface CopingSettingsIssue {
+  code: 'CP01' | 'CP02';
+  key: keyof CopingRebarSettings;
+  message: string;
+}
+
+/**
+ * Checks the settings against the ranges. CP01: a value is not a finite number or is out of range (W).
+ * CP02: the shear leg count is odd (the 폐합 bars come in pairs of legs).
+ */
+export function copingSettingsIssues(s: CopingRebarSettings): CopingSettingsIssue[] {
+  const out: CopingSettingsIssue[] = [];
+  for (const key of Object.keys(COPING_REBAR_RANGES) as (keyof CopingRebarSettings)[]) {
+    const v = s[key];
+    const [lo, hi] = COPING_REBAR_RANGES[key];
+    if (!Number.isFinite(v) || v < lo || v > hi) {
+      out.push({ code: 'CP01', key, message: `CP01 ${key} ${v} 범위 밖 (${lo}–${hi})` });
+    }
+  }
+  if (Number.isFinite(s.shearLegs) && s.shearLegs % 2 !== 0) {
+    out.push({ code: 'CP02', key: 'shearLegs', message: `CP02 전단철근 다리 수 ${s.shearLegs}는 홀수 (짝수만 허용)` });
+  }
+  return out;
+}