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>

vite.config.ts

@@ -0,0 +1,15 @@
+import { defineConfig } from 'vite'
+import react from '@vitejs/plugin-react'
+import path from 'path'
+
+export default defineConfig({
+  plugins: [react()],
+  resolve: {
+    alias: {
+      '@': path.resolve(__dirname, './src'),
+    },
+  },
+  worker: {
+    format: 'es',
+  },
+})