Implement graceful shutdown using context and OS signals

[RD2W]

This PR implements graceful shutdown functionality for the application using context and OS signals. Key changes include:

• Replaced done channels with context for better cancellation propagation
• Added OS signal handling (SIGINT, SIGTERM, SIGHUP) in main.go
• Updated Service and Logger components to use context instead of done channels
• Modified all tests to use context instead of done channels
• Ensured all goroutines properly respond to context cancellation

This provides a more robust and standard way to handle application shutdown, allowing for proper cleanup of resources when the application receives OS signals.