Enhance security and validation across multiple routes:

- Escape XML and HTML special characters to prevent injection attacks.
- Implement rate limiting for various endpoints to mitigate abuse.
- Add validation for email formats, password lengths, and field limits.
- Ensure proper access control for recordings and room management.

server/middleware/auth.js

@@ -3,7 +3,11 @@ import { v4 as uuidv4 } from 'uuid';
 import { getDb } from '../config/database.js';
 import redis from '../config/redis.js';
 
-const JWT_SECRET = process.env.JWT_SECRET || 'fallback-secret-change-me';
+if (!process.env.JWT_SECRET) {
+  console.error('FATAL: JWT_SECRET environment variable is not set. ');
+  process.exit(1);
+}
+const JWT_SECRET = process.env.JWT_SECRET;
 
 export async function authenticateToken(req, res, next) {
   const authHeader = req.headers.authorization;