feat(core): parse P1 workbook and build T-type pier shape

- parse Excel input by header strings (pier, IP, bearing tables)
- DMS azimuth parser (E03), input validation (E01, E02)
- pure geometry: axis, bearings, stepped coping, column, footing, piles, blinding
- warnings W01, W02, W05, W07, I01
- regression tests against spec.md section 12 (P1)

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

tsconfig.json

@@ -0,0 +1,14 @@
+{
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+    "target": "ES2022",
+    "module": "ESNext",
+    "moduleResolution": "Bundler",
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
+    "strict": true,
+    "noEmit": true,
+    "skipLibCheck": true,
+    "isolatedModules": true,
+    "types": ["node"]
+  },
+  "include": ["src", "tests"]
+}