feat(frpLogger): add real-time instance log streaming functionality

Implement cross-platform log streaming for frpc instances with support for Windows, systemd, and init.d systems. Includes WebSocket API endpoint for real-time log streaming, token validation, and instance ownership checks. Update README and API documentation to reflect new functionality.

The implementation handles:
- Platform-specific log collection (Windows Event Log, journalctl, log files)
- WebSocket-based real-time streaming
- Token validation and instance access control
- Log level parsing and formatting
- Historical log retrieval since service start

README.md

@@ -63,12 +63,13 @@ For detailed API documentation, please see [docs/api.md](docs/api.md)
 - [x] Add session list API
 - [x] Add session management API
 - [ ] Add user config modify API
-- [ ] Add frpc instance running status management API
-- [ ] Add frpc instance log display API
-- [ ] Fix random database lock when processing logs
+- [x] Add frpc instance running status management API
+- [x] Add frpc instance log display API
+- [x] Fix random database lock when processing logs
 - [ ] Add frpc createdBy storage and display
 - [x] Fix backend can still start frpc instance when it is already running
 - [ ] Develop an agent software to handle windows service management
+- [ ] Refactor all log output level to be more clear
 
 ## License