feat(rebar): add 3D coupler modeling for P1/P2 (368) and P4/P5 (35) with separate summary table rows

tests/rebar-summary.test.ts

@@ -27,7 +27,8 @@ describe('③ 철근표 요약 (P1)', () => {
   it('column: P1 230, P2 230, couplers 368, P3 38, P5 19, P4 8, P6 32', () => {
     expect(count('P1')).toBe(230);
     expect(count('P2')).toBe(230);
-    expect(count('커플러')).toBe(368);
+    expect(count('주철근 커플러')).toBe(368);
+    expect(count('띠철근 커플러')).toBe(35);
     expect(count('P3')).toBe(38);
     expect(count('P5')).toBe(19);
     expect(count('P4')).toBe(8);