Replace the legacy Unix socket log communication between `ctrld start` and
`ctrld run` with a modern HTTP-based system for better reliability and
maintainability.
Benefits:
- More reliable communication protocol using standard HTTP
- Better error handling and connection management
- Cleaner separation of concerns with dedicated endpoints
- Easier to test and debug with HTTP-based communication
- More maintainable code with proper abstraction layers
This change maintains backward compatibility while providing a more robust
foundation for inter-process communication between ctrld commands.
