feat: implement cache layer, CSP improvements, and database performance optimizations

- Add Redis cache implementation with LRU eviction
- Enhance Content Security Policy with nonce generation
- Optimize database queries with connection pooling
- Add cache invalidation API endpoints
- Improve security monitoring performance

scripts/validate-csp-implementation.ts

@@ -1,12 +1,11 @@
 #!/usr/bin/env tsx
 
 import {
-  buildCSP,
   validateCSP,
-  generateNonce,
   detectCSPBypass,
   testCSPImplementation,
 } from "../lib/csp";
+import { buildCSP, generateNonce } from "../lib/csp-server";
 
 interface CSPTestResult {
   test: string;