feat: initialize Annual Gala Interactive System monorepo

- Set up pnpm workspace with 4 packages: shared, server, client-mobile, client-screen
- Implement Redis atomic voting with Lua scripts (HINCRBY + distributed lock)
- Add optimistic UI with IndexedDB queue for offline resilience
- Configure Socket.io with auto-reconnection (infinite retries)
- Separate mobile (Vant) and big screen (Pixi.js) dependencies

Tech stack:
- Frontend Mobile: Vue 3 + Vant + Socket.io-client
- Frontend Screen: Vue 3 + Pixi.js + GSAP
- Backend: Express + Socket.io + Redis + Prisma/MySQL

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

packages/shared/package.json

@@ -0,0 +1,39 @@
+{
+  "name": "@gala/shared",
+  "version": "1.0.0",
+  "private": true,
+  "type": "module",
+  "main": "./dist/index.js",
+  "module": "./dist/index.js",
+  "types": "./dist/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./dist/index.d.ts",
+      "import": "./dist/index.js"
+    },
+    "./types": {
+      "types": "./dist/types/index.d.ts",
+      "import": "./dist/types/index.js"
+    },
+    "./constants": {
+      "types": "./dist/constants/index.d.ts",
+      "import": "./dist/constants/index.js"
+    },
+    "./utils": {
+      "types": "./dist/utils/index.d.ts",
+      "import": "./dist/utils/index.js"
+    }
+  },
+  "scripts": {
+    "build": "tsup src/index.ts src/types/index.ts src/constants/index.ts src/utils/index.ts --format esm --dts --clean",
+    "dev": "tsup src/index.ts src/types/index.ts src/constants/index.ts src/utils/index.ts --format esm --dts --watch",
+    "typecheck": "tsc --noEmit"
+  },
+  "dependencies": {
+    "zod": "^3.24.1"
+  },
+  "devDependencies": {
+    "tsup": "^8.3.5",
+    "typescript": "^5.7.3"
+  }
+}