Implement email alert system with WhatsApp notifications

- Added alerts processing logic in src/alerts.py to analyze threads and send WhatsApp alerts based on configured time frames.
- Created FastAPI application in src/app.py to manage threads, display configurations, and trigger alert processing.
- Developed database models and utility functions in src/database.py for managing threads and messages.
- Integrated Twilio API for sending WhatsApp messages in src/whatsapp_sender.py.
- Implemented Zoho email client in src/zoho_client.py to fetch emails and check for replies.
- Added configuration management for email settings and alert parameters.
- Established auto-processing loop for periodic email syncing and alert generation.

templates/base.html

@@ -13,6 +13,9 @@
       <nav>
         <a href="/">Threads</a>
   <a href="/config">Config</a>
+        <form action="/sync_emails" method="post" style="display:inline-block; margin-left:12px;">
+          <button type="submit">Process Emails</button>
+        </form>
       </nav>
     </div>
   </header>