fixed pyservectl linter errors and formatting

pyserve/ctl/_daemon.py

@@ -11,9 +11,11 @@ import os
 import signal
 import sys
 from pathlib import Path
+from types import FrameType
+from typing import Optional
 
 
-def main():
+def main() -> None:
     parser = argparse.ArgumentParser(description="PyServe Daemon")
     parser.add_argument("--config", required=True, help="Configuration file path")
     parser.add_argument("--state-dir", required=True, help="State directory path")
@@ -63,7 +65,7 @@ def main():
 
     runner = ServiceRunner(config, state_manager)
 
-    def signal_handler(signum, frame):
+    def signal_handler(signum: int, frame: Optional[FrameType]) -> None:
         logger.info(f"Received signal {signum}, shutting down...")
         runner.stop()