Initial commit: Western Shooter - Complete implementation

Retro western vertical shooter inspired by Gun.Smoke, built with
TypeScript and WebGL2. Features 3-direction shooting, vertical
scrolling, economy/shop loop, boss fights, and CRT shader effects.

Phases implemented:
- Phase 1: Engine skeleton (WebGL2 renderer, fixed timestep loop, input)
- Phase 2: Shooting identity (3-dir shooting, bullet pools, collision)
- Phase 3: Enemies & patterns (JSON waves, 4 enemy types, parallax bg)
- Phase 4: Economy loop (pickups, shop, upgrades, HUD)
- Phase 5: Boss system (3 bosses, wanted posters, multi-phase attacks)
- Phase 6: Shader layer (CRT effects, bloom, scanlines, screen shake)
- Phase 7: Performance (VAO batching, O(1) allocation, stress testing)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tsconfig.json

@@ -0,0 +1,20 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "resolveJsonModule": true,
+    "declaration": true,
+    "declarationMap": true,
+    "sourceMap": true,
+    "outDir": "./dist",
+    "rootDir": "./src",
+    "lib": ["ES2022", "DOM", "DOM.Iterable"]
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "dist"]
+}