Add server monitoring functionality and update Makefile and requirements

- Introduced a new server monitoring module in `run_helper.py` with graceful shutdown handling.
- Updated `.gitignore` to include PID files.
- Added `test-monitor` target in `Makefile` for testing the server monitoring module.
- Included `psutil` in `requirements.txt` for system monitoring capabilities.

requirements.txt

@@ -4,6 +4,9 @@ aiogram~=3.10.0
 # Logging
 loguru==0.7.2
 
+# System monitoring
+psutil~=6.1.0
+
 # Testing
 pytest==8.2.2
 pytest-asyncio==1.1.0