feat(agent): add persistent klogging settings

- Add settings API and UI to toggle keylog
- Persist preference in settings.json
- Expose klogging state in status endpoint
- Inject build version into web console
- Bump version automatically on build

lib/agent/agent.go

@@ -97,6 +97,7 @@ func (a *Agent) Serve() error {
 	mux.HandleFunc("/api/v1/webcam/frame", a.handleWebcamFrame)
 	mux.HandleFunc("/api/v1/exec", a.handleExec)
 	mux.HandleFunc("/api/v1/startup", a.handleStartup)
+	mux.HandleFunc("/api/v1/settings", a.handleSettings)
 	mux.HandleFunc("/api/v1/input/click", a.handleClick)
 	mux.HandleFunc("/api/v1/input/key", a.handleKey)
 	mux.HandleFunc("/api/v1/input/text", a.handleText)