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.

package.json

@@ -29,6 +29,7 @@
     "@astrolib/analytics": "^0.6.1",
     "@astrolib/seo": "^1.0.0-beta.8",
     "@fontsource-variable/inter": "^5.1.1",
+    "@google/generative-ai": "^0.24.1",
     "@tippyjs/react": "^4.2.6",
     "@types/react": "^19.0.10",
     "@types/react-dom": "^19.0.4",
@@ -38,6 +39,7 @@
     "csrf": "^3.1.0",
     "dotenv": "^16.4.7",
     "form-data": "^4.0.2",
+    "jsonwebtoken": "^9.0.2",
     "limax": "4.1.0",
     "lodash.merge": "^4.6.2",
     "luxon": "^3.6.1",
@@ -61,6 +63,7 @@
     "@tailwindcss/typography": "^0.5.16",
     "@types/eslint__js": "^8.42.3",
     "@types/js-yaml": "^4.0.9",
+    "@types/jsonwebtoken": "^9.0.9",
     "@types/lodash.merge": "^4.6.9",
     "@types/mdx": "^2.0.13",
     "@typescript-eslint/eslint-plugin": "^8.21.0",