feat(rebar,view): 받침 기준 — project-wide choice between Excel z (default) and drawing EL.X, with per-bearing drawing input on ②

The project has one basis: 엑셀 z (default) or 도면 EL.X. On ②, the bearing card lists EL.X, h1 and h2 for each bearing
(per pier), with a button to fill the reference values. With the drawing basis the model takes the drawing EL.X as the
bearing height; the coping tops stay within the 5 mm tolerance, the front block is 164 mm and the back 139 mm (excluding the
pad). The check compares EL.X − h1 − h2 with the Excel-basis coping top. The basis and the drawing values are saved in the
project file (optional fields). Changes regenerate every pier at once.

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

src/core/project.ts

@@ -31,6 +31,10 @@ export interface ProjectFile {
   history: { version: string; note: string; at: string }[];
   /** ③ 공통 설정 (fck · fy). Absent in older files: the defaults are used. */
   common?: Material;
+  /** 받침 기준 (project-wide): 'excel' (default) or 'drawing'. Absent = 'excel'. */
+  bearingBasis?: 'excel' | 'drawing';
+  /** 도면 받침 값 per pier name (EL.X in m, h1 and h2 in mm). */
+  bearingDrawing?: Record<string, { no: number; elx: number; h1: number; h2: number }[]>;
   /** ② 부재별 fck (MPa). Absent in older files: every member uses the 공통 fck. */
   fckByMember?: FckByMember;
 }