Initial commit: Arcanum TD — medieval fantasy tower defense

Vite + React + PixiJS + TypeScript. Features:
- 4-level campaign (King's Road → Obsidian Keep)
- Isometric 2.5D grid with ley-line mechanics
- ECS architecture (entities, components, systems)
- 4 tower types, hero spellcaster, 10+ enemy types
- Lich King boss with 3-phase AI
- Meta-progression: essence, rune unlocks
- Full UI redesign with fantasy design system

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tsconfig.node.json

@@ -0,0 +1,24 @@
+{
+  "compilerOptions": {
+    "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.node.tsbuildinfo",
+    "target": "es2023",
+    "lib": ["ES2023"],
+    "module": "esnext",
+    "types": ["node"],
+    "skipLibCheck": true,
+
+    /* Bundler mode */
+    "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
+    "verbatimModuleSyntax": true,
+    "moduleDetection": "force",
+    "noEmit": true,
+
+    /* Linting */
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "erasableSyntaxOnly": true,
+    "noFallthroughCasesInSwitch": true
+  },
+  "include": ["vite.config.ts"]
+}