Update dashboard community links to use env vars, add deploy configs

- Dashboard community links now use .env values like community page
- Removed hardcoded social media URLs from dashboard
- Added deploy folder with nginx and systemd service configs
- Moved linktree page to public route
- Various backend and auth context updates

backend/package.json

@@ -5,7 +5,7 @@
   "scripts": {
     "dev": "tsx watch src/index.ts",
     "build": "tsc",
-    "start": "node dist/index.js",
+    "start": "NODE_ENV=production node dist/index.js",
     "db:generate": "drizzle-kit generate",
     "db:migrate": "tsx src/db/migrate.ts",
     "db:studio": "drizzle-kit studio"