Add Hono backend with PostgreSQL, auth, cloud saves, and leaderboard

Server app (apps/server) with Hono framework and Drizzle ORM:
- PostgreSQL schema: users, saves, leaderboard, achievements tables
- Anonymous auth with UUID tokens, optional email/password linking
- Cloud save API: list, get, upsert, delete with auto-save hook
- Leaderboard API: per-category rankings with score submission
- CORS configured for dev server ports
- Typed middleware with Hono env variables

Frontend cloud save integration:
- API client with auth token management in localStorage
- useCloudSave hook auto-saves every 300 ticks when authenticated
- Vite env type declarations for VITE_API_URL

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

apps/server/package.json

@@ -0,0 +1,29 @@
+{
+  "name": "@ai-tycoon/server",
+  "version": "0.0.1",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "tsx watch src/index.ts",
+    "build": "tsc && tsx src/index.ts",
+    "typecheck": "tsc --noEmit",
+    "db:generate": "drizzle-kit generate",
+    "db:migrate": "drizzle-kit migrate",
+    "db:push": "drizzle-kit push"
+  },
+  "dependencies": {
+    "@ai-tycoon/shared": "workspace:*",
+    "@hono/node-server": "^1.13.8",
+    "drizzle-orm": "^0.44.2",
+    "hono": "^4.7.10",
+    "postgres": "^3.4.7",
+    "uuid": "^11.1.0"
+  },
+  "devDependencies": {
+    "@ai-tycoon/tsconfig": "workspace:*",
+    "@types/node": "^25.6.0",
+    "drizzle-kit": "^0.31.1",
+    "tsx": "^4.19.4",
+    "typescript": "^5.8.3"
+  }
+}