fix(view): EL.X = block top including the 50 mm mortar; coping top = EL.X − h1 − h2 (matches the model)

With this definition the drawing's coping top matches the model's coping top to within 1 mm on all ten bearings. The earlier
0.211 m offset came from reading EL.X as the solplate top, which was wrong. The reference table now uses EL.X − h1 − h2,
and the check tests the match.

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

tests/bearing-ref.test.ts

@@ -31,14 +31,14 @@ describe('교량받침 reference (도면값, 읽기 전용, 1단계)', () => {
     }
   });
 
-  it('the drawing EL.X − E sits a constant 0.211 m below the model coping top on all ten bearings (Q16 diagnostic)', () => {
+  it('EL.X = block top incl. the 50 mm mortar: coping top = EL.X − h1 − h2 matches the model on all ten bearings (within 2 mm)', () => {
     const m = buildPier(loadP1());
     const back = m.blocks.filter((b) => b.row === '후열');
     const diffs = BEARING_ELEVATION_REF.map((r) => {
       const modelTop = r.row === '전열' ? m.segments[r.no - 1].top : back[r.no - 6].bottom;
-      return modelTop - (r.elx - r.E / 1000);
+      return modelTop - (r.elx - (r.h1 + r.h2) / 1000);
     });
-    for (const d of diffs) expect(d).toBeCloseTo(0.211, 2);
+    for (const d of diffs) expect(Math.abs(d)).toBeLessThan(0.002);
   });
 });