Add spam detection and manual review request feature in contact form

- Integrated Gemini AI for spam detection in the contact form API, returning a token for manual review requests if spam is detected.
- Implemented a manual review UI in the Form.astro component, allowing users to submit their email and justification for review.
- Updated email handler to send manual review requests to a designated email address.
- Enhanced rate limiter configuration to allow more attempts in a shorter duration for better user experience.
- Added new dependencies: jsonwebtoken and @types/jsonwebtoken for handling JWTs in the spam detection process.

src/utils/email-handler.ts

@@ -54,8 +54,8 @@ function initializeTransporter() {
 
 // Rate limiter configuration
 const rateLimiter = new RateLimiterMemory({
-  points: 5, // 5 attempts
-  duration: 3600, // per hour
+  points: 20, // 20 attempts
+  duration: 300, // per 5 minutes
 });
 
 // CSRF protection