feat(plan): 형상계획 ②에 교대 부재 목록과 부재별 카드 추가 (1단계)

- 부재 · 교대 목록(받침, 벽체·흉벽, 날개벽, 접속슬래브, 지반·지층)과 각 행의 값·변경 표시 (src/core/abut/member-list.ts)
- 행을 누르면 그 부재의 카드만 표시. 날개벽 형식은 별도 카드로 분리
- 접속슬래브·지반·지층은 값만 표시 (입력은 2단계)
- 모델 변경 없음. 테스트 630건 통과, 타입 검사·빌드 통과. 브라우저 시각 확인은 미실시

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

src/core/abut/member-list.ts

@@ -0,0 +1,66 @@
+import type { WingForm } from './geometry';
+import { ABUT_SHAPE_DEFAULT, type AbutShape } from './shape';
+
+/** 부재 · 교대 list in ② (시안): the card each row opens. */
+export type AbutMemberId = 'bearing' | 'shape' | 'wing' | 'slab' | 'ground';
+
+/** Cards that take input in this step; slab and ground only show their values (phase 1, 2026-11-03). */
+export const ABUT_MEMBER_EDITABLE: Record<AbutMemberId, boolean> = {
+  bearing: true,
+  shape: true,
+  wing: true,
+  slab: false,
+  ground: false,
+};
+
+const WING_LABEL: Record<WingForm, string> = { general: '일반형', short: '단축형', none: '없음' };
+
+/** The subset of an abutment record the list reads. */
+export interface AbutMemberInput {
+  bearings: { seatEl?: number }[];
+  shape?: Partial<AbutShape>;
+  wings?: { left: WingForm; right: WingForm };
+  groundEl: number;
+}
+
+export interface AbutMemberRow {
+  id: AbutMemberId;
+  label: string;
+  summary: string;
+  /** True when the value differs from the default (or a 받침 has its own 교좌면 EL). */
+  changed: boolean;
+}
+
+/**
+ * The five rows of the 부재 · 교대 list. `slabWidth` is the computed 접속슬래브 폭 text, passed in
+ * so this stays a pure function of the record.
+ */
+export function abutMemberRows(rec: AbutMemberInput, slabWidth: string): AbutMemberRow[] {
+  const shape = { ...ABUT_SHAPE_DEFAULT, ...(rec.shape ?? {}) };
+  const shapeChanged = (Object.keys(ABUT_SHAPE_DEFAULT) as (keyof AbutShape)[]).some(
+    (key) => (rec.shape?.[key] ?? ABUT_SHAPE_DEFAULT[key]) !== ABUT_SHAPE_DEFAULT[key],
+  );
+  const wings = rec.wings ?? { left: 'general' as WingForm, right: 'general' as WingForm };
+  return [
+    {
+      id: 'bearing',
+      label: '교량받침·받침블럭·솔플레이트',
+      summary: `${rec.bearings.length}개 · z = 패드 상면`,
+      changed: rec.bearings.some((b) => b.seatEl !== undefined),
+    },
+    {
+      id: 'shape',
+      label: '벽체·흉벽',
+      summary: `벽체 두께 ${shape.wallThicknessMm} · 흉벽 ${shape.parapetHeightMm}`,
+      changed: shapeChanged,
+    },
+    {
+      id: 'wing',
+      label: '날개벽',
+      summary: `좌 ${WING_LABEL[wings.left]} · 우 ${WING_LABEL[wings.right]}`,
+      changed: wings.left !== 'general' || wings.right !== 'general',
+    },
+    { id: 'slab', label: '접속슬래브', summary: slabWidth, changed: false },
+    { id: 'ground', label: '지반·지층', summary: `지반고 ${rec.groundEl.toFixed(3)} m`, changed: false },
+  ];
+}