Fix Docker build and production server infrastructure

- Add SKIP_ENV_VALIDATION to bypass Zod env check during next build
- Bundle custom server.ts with esbuild so production uses Socket.io
- Create worker entry point (src/worker.ts) with all BullMQ workers
- Add esbuild build scripts for server and worker bundles
- Fix Dockerfile.worker to include its own build stage
- Fix pre-commit hook to work without global pnpm
- Add CLAUDE.md with project conventions and quick reference

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

package.json

@@ -4,7 +4,9 @@
   "private": true,
   "scripts": {
     "dev": "next dev",
-    "build": "next build",
+    "build": "next build && pnpm build:server",
+    "build:server": "esbuild src/server.ts --bundle --platform=node --target=node20 --format=cjs --outdir=dist --packages=external --tsconfig=tsconfig.server.json",
+    "build:worker": "esbuild src/worker.ts --bundle --platform=node --target=node20 --format=cjs --outdir=dist --packages=external --tsconfig=tsconfig.server.json",
     "start": "next start",
     "lint": "next lint",
     "format": "prettier --write \"src/**/*.{ts,tsx,json,css}\"",
@@ -89,6 +91,7 @@
     "@types/react-dom": "^19.0.0",
     "@vitest/coverage-v8": "^4.1.0",
     "autoprefixer": "^10.4.27",
+    "esbuild": "^0.25.0",
     "dotenv": "^17.3.1",
     "drizzle-kit": "^0.30.0",
     "eslint": "^9.0.0",