Add testing suite for monitoring system

[yossiovadia]

Task

Create comprehensive tests for the monitoring system using dogfooding approach.

Test Scenarios

1. Basic approval detection

   • Create session with command requiring approval
   • Verify alert is generated
   • Test approval response forwarding

2. Reminder system

   • Let alert sit for 5+ minutes
   • Verify reminder is sent
   • Test snooze functionality

3. Multiple sessions

   • Run 2-3 sessions simultaneously
   • Verify alerts are session-specific
   • Test handling multiple pending approvals

4. Response types

   • Test numeric responses (1/2/3)
   • Test natural language (approve/always/deny)
   • Test invalid responses

5. Cleanup

   • Kill session while monitor running
   • Verify monitor exits cleanly
   • Verify alert files are cleaned up

Acceptance Criteria

• All test scenarios pass
• Documentation includes test results
• Edge cases are handled gracefully

Related

Part of #8, depends on #9, #10, #11