Implement location tracking and suspicious login detection

- Added `track_login_location` function to monitor user login locations.
- Introduced `LoginLocation` model to store login details including IP and geolocation.
- Created `LocationApprovalToken` model for managing location approval tokens.
- Enhanced OTP verification to include location tracking and alerts for suspicious logins.
- Implemented email notifications for suspicious login attempts and location approvals.
- Added `login_history` route to display user's login activity.
- Updated templates for login history and email notifications.
- Configured mail settings and added dependencies for email functionality.
- Introduced utility classes for mail and location services.

.env.example

@@ -19,6 +19,18 @@ DATABASE_URL=sqlite:///app.db
 # Application Settings
 DEBUG=True
 
+# Mail Configuration (for location alerts and notifications)
+MAIL_SERVER=smtp.gmail.com
+MAIL_PORT=587
+MAIL_USE_TLS=true
+MAIL_USERNAME=your-email@gmail.com
+MAIL_PASSWORD=your-app-password
+MAIL_DEFAULT_SENDER=noreply@flask2fa.com
+
+# Location Security Settings
+MAX_LOGIN_ATTEMPTS=5
+SUSPICIOUS_LOGIN_THRESHOLD_KM=100
+
 # Security Headers (Production only)
 # SESSION_COOKIE_SECURE=True
 # SESSION_COOKIE_HTTPONLY=True