refactor: fix biome linting issues and update project documentation

- Fix 36+ biome linting issues reducing errors/warnings from 227 to 191
- Replace explicit 'any' types with proper TypeScript interfaces
- Fix React hooks dependencies and useCallback patterns
- Resolve unused variables and parameter assignment issues
- Improve accessibility with proper label associations
- Add comprehensive API documentation for admin and security features
- Update README.md with accurate PostgreSQL setup and current tech stack
- Create complete documentation for audit logging, CSP monitoring, and batch processing
- Fix outdated project information and missing developer workflows

app/api/csrf-token/route.ts

@@ -5,7 +5,7 @@
  * It generates a new token and sets it as an HTTP-only cookie.
  */
 
-import { NextRequest } from "next/server";
+import type { NextRequest } from "next/server";
 import { generateCSRFTokenResponse } from "../../../middleware/csrfProtection";
 
 /**
@@ -14,6 +14,6 @@ import { generateCSRFTokenResponse } from "../../../middleware/csrfProtection";
  * Generates and returns a new CSRF token.
  * The token is also set as an HTTP-only cookie for automatic inclusion in requests.
  */
-export function GET(request: NextRequest) {
+export function GET() {
   return generateCSRFTokenResponse();
-}
+}