- Replaced counter-based signal handling with flag-based approach
- Added sigint_handled flag to prevent multiple signal handler executions
- First Ctrl+C: Sets flag and initiates graceful shutdown
- Second Ctrl+C: Forces immediate exit with os._exit(1)
- Prevents race conditions and multiple signal handler calls
- Ensures proper single-signal behavior for graceful shutdown

This resolves the issue where a single Ctrl+C was triggering both graceful shutdown and immediate exit messages.