feat: complete house plan maker application

Full-featured house/apartment floor plan editor with:

- Turborepo monorepo (React/Vite client, Fastify/Prisma server, shared Zod schemas)
- 2D room editor with walls, doors, windows, furniture, electrical elements
- 3D room preview with Three.js (auto-hide nearest walls, bird's eye default)
- Wall projection views with interactive drag (elevation, position)
- Apartment floor plan view with room positioning
- Copy/paste, alignment tools, measurement tool, annotations
- Item-attached annotations with leader lines (visible on projections)
- Door open direction (LEFT/RIGHT/INWARD/OUTWARD) with swing arc
- Floor type textures (wood, tile, concrete, laminate, herringbone)
- Wall color picker for 3D view
- Furniture: bed, desk, wardrobe, sofa, table, chair, shelf, nightstand, dresser, bookcase, TV (with stand toggle), AC unit
- Furniture elevation support (wall-mounted items)
- Auto-save with dirty state tracking, batch save API
- Rotation-aware collision detection (SAT/OBB) with 3D elevation check
- Rotation-aware hit testing
- i18n (English/Russian) with locale-aware number formatting
- Dark mode with system preference detection
- Undo/redo, keyboard shortcuts, scale bar
- PDF/PNG/JSON export and JSON import
- Focus trap modal, toast notifications, tooltips
- Responsive layout with overlay palettes

package.json

@@ -0,0 +1,27 @@
+{
+  "name": "house-plan-maker",
+  "private": true,
+  "type": "module",
+  "workspaces": [
+    "apps/*",
+    "packages/*"
+  ],
+  "scripts": {
+    "dev": "turbo run dev",
+    "build": "turbo run build",
+    "test": "turbo run test",
+    "lint": "turbo run lint",
+    "format": "prettier --write \"**/*.{ts,tsx,js,jsx,json,css,md}\""
+  },
+  "packageManager": "npm@10.8.0",
+  "devDependencies": {
+    "@eslint/js": "^9.18.0",
+    "eslint": "^9.18.0",
+    "eslint-plugin-react-hooks": "^7.0.1",
+    "globals": "^15.14.0",
+    "prettier": "^3.4.0",
+    "turbo": "^2.4.0",
+    "typescript": "^5.7.0",
+    "typescript-eslint": "^8.20.0"
+  }
+}