Integrate Cloudflare Turnstile for CAPTCHA verification across authentication flows

- Added TurnstileCaptcha component for handling CAPTCHA verification.
- Updated login, registration, and account management pages to include CAPTCHA validation.
- Implemented rate limiting middleware to prevent abuse on login and registration endpoints.
- Refactored Swal import to use dynamic import for better performance.
- Enhanced shared links and editor components with improved error handling and user feedback.
- Updated environment variable configurations for Turnstile integration.
- Added example .env files for frontend and backend services to include new Turnstile and rate limiting settings.

Author: glad432

Backend/Genai/.env.example

@@ -0,0 +1,30 @@
+# Google Gemini API
+GOOGLE_API_KEY=
+GEMINI_MODEL=
+GEMINI_MODEL_1=
+
+# JWT Authentication
+JWT_SECRET=
+
+# Google reCAPTCHA v3
+RECAPTCHA_SECRET_KEY=
+RECAPTCHA_MIN_SCORE=0.5
+RECAPTCHA_TIMEOUT=3.0
+
+# Redis credentials
+REDIS_HOST=
+REDIS_PORT=6379
+REDIS_PASSWORD=
+
+# Timeout for Gemini streams
+STREAM_TIMEOUT_SECONDS=240
+
+# Size limits (bytes)
+MAX_DESCRIPTION_BYTES=4096
+MAX_CODE_SIZE_BYTES=524288
+
+# CORS allowed origins (comma-separated for exact matches)
+ALLOWED_ORIGINS=
+
+# Local development port (optional)
+PORT=5001