feat: add comprehensive issue automation system

- Auto-assign issues when users select 'Yes' in issue form
- Support /assign command for manual assignment
- Enforce 2-issue limit per user
- Daily deadline checks with priority-based timeouts (3/6/8 days)
- Warning notifications 24h before deadline
- Project V2 integration with OS - TASK TRACKER
- Idempotent project sync with status updates
- Comprehensive error handling and logging
- Production-ready workflow with timeouts and concurrency control

Author: roshankumar0036singh