feat(view,rebar): column diameter D as a free input on ② (1200–3000 mm, 50 mm steps), with three checks

D is an input on the column card (default 2000 mm). The 3D column, the piles of a cast-in pier and the column rebar follow it;
n_div stays 46. Three checks run on each regenerate and appear in 알림: D below the Level width (2100), D + 2c within the
coping width, and the 주철근 arc spacing ≥ max(1.5·d_b, 40). Spec §5.2 records the rule (approved 2026-10-23).

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

src/main.ts

@@ -17,6 +17,7 @@ import { DEFAULT_MATERIAL, FCK_MEMBERS, fyOf, GRADE_CHOICES, isAssumedMaterial,
 import { buildQuantity, quantityRows, type Quantity, type QuantityLine } from './core/rebar/quantity';
 import { parseDrawingRows } from './core/drawing-import';
 import { parseBearingElevationTable, parseSolplateTable, readDxfTexts } from './core/dxf-table';
+import { columnDiameterIssues } from './core/column-check';
 import { P1_COPING_GEOM } from './core/coping-geom';
 import { applyBearingRules, BEARING_ELEVATION_REF, BEARING_RULES_DEFAULT, type BearingBasis, type BearingRules, type DrawingBearing, DRAWING_TOL_MM, drawingCopingCheck, SOLPLATE_REF, SOLPLATE_T_RULE, solplateTs, withDrawingBasis } from './core/bearing-ref';
 
@@ -69,7 +70,7 @@ const CRS = '국토좌표계 (x = 동, y = 북)';
 const MEMBERS: { id: MemberId; label: string; keys: EditableKey[]; note: string }[] = [
   { id: 'bearing', label: '교량받침·받침블럭·솔플레이트', keys: [], note: '받침 상세(C3)는 Q16 결정 후 추가합니다. 지금은 표시만 합니다.' },
   { id: 'coping', label: '코핑', keys: ['copingWidthMm', 'copingLengthMm', 'copingH1Mm', 'copingH2Mm', 'levelWidthMm'], note: '폭, 길이, 끝단 높이 h1, 테이퍼 높이 h2, Level 폭을 입력합니다. 계단 위치·단차선 입력은 다음 단계에서 추가합니다.' },
-  { id: 'column', label: '기둥', keys: [], note: '기둥 지름 입력은 다음 단계에서 추가합니다. 높이와 위치는 계산값입니다.' },
+  { id: 'column', label: '기둥', keys: ['columnDiameterMm'], note: '기둥 직경 D를 입력합니다 (1200–3000 mm, 50 mm 단위). 높이와 위치는 계산값입니다.' },
   { id: 'footing', label: '확대기초 · 말뚝', keys: ['pileLengthMm'], note: '말뚝 길이를 입력합니다. 열별 본수는 다음 단계에서 추가합니다.' },
   { id: 'ground', label: '지반·지층', keys: [], note: '지반고는 입력값을 표시만 합니다. 지층 입력은 다음 단계에서 추가합니다.' },
 ];
@@ -196,6 +197,7 @@ animate();
 function withCopingDefaults(input: PierInput): PierInput {
   return {
     ...input,
+    columnDiameterMm: input.columnDiameterMm ?? 2000,
     copingH1Mm: input.copingH1Mm ?? P1_COPING_GEOM.h1,
     copingH2Mm: input.copingH2Mm ?? P1_COPING_GEOM.h2,
     levelWidthMm: input.levelWidthMm ?? P1_COPING_GEOM.levelWidth,
@@ -218,6 +220,9 @@ function buildEntry(rawInput: PierInput, checked: boolean): Pier {
     try {
       model = buildPier(modelInput);
       validatePier(input, model, issues);
+      for (const message of columnDiameterIssues(modelInput.columnDiameterMm ?? 2000, model)) {
+        issues.push({ code: 'D01', level: 'E', pier: input.name, message });
+      }
     } catch (err) {
       issues.push({ code: '미실시', level: 'E', pier: input.name, message: (err as Error).message });
     }