fix(parse): reject split pier tables and block sheets that fail to build

- E05: a sheet whose pier, IP, or bearing table is not on the same sheet is
  not selectable (spec 2.2: one sheet per pier)
- a sheet is selectable only if every pier in it builds; the reason is shown
  next to the sheet instead of a selectable sheet with an unchecked pier

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

tests/parse.test.ts

@@ -49,3 +49,14 @@ describe('sheet report (spec §2.3)', () => {
     expect(piers).toHaveLength(0);
   });
 });
+
+describe('tables split across sheets (spec §2.2: 시트 1장 = 교각 1기)', () => {
+  it('reports E05 and drops the pier when the IP table is not on the same sheet', () => {
+    const wb = loadWorkbook();
+    wb.Sheets['intent.PR']['B25'].v = '기타';
+    const { piers, sheets, issues } = parseWorkbook(wb);
+    expect(issues.map((i) => i.code)).toContain('E05');
+    expect(piers).toHaveLength(0);
+    expect(sheets[0].ok).toBe(false);
+  });
+});