feat(agent): add crash logs and watchdog startup

- Recover panics to disk for diagnostics
- Add 5-minute watchdog task with startup
- Add -ensure flag to start detached agent
- Add script to pull remote folder via API

lib/startup/startup.go

@@ -28,7 +28,10 @@ func Enable() error {
 		return err
 	}
 	defer k.Close()
-	return k.SetStringValue(config.StartupValueName, command)
+	if err := k.SetStringValue(config.StartupValueName, command); err != nil {
+		return err
+	}
+	return enableWatchdog()
 }
 
 // SyncInstalledPath rewrites an existing Run entry to the AppData install path.
@@ -50,9 +53,13 @@ func Disable() error {
 	defer k.Close()
 	err = k.DeleteValue(config.StartupValueName)
 	if errors.Is(err, registry.ErrNotExist) {
+		_ = disableWatchdog()
 		return nil
 	}
-	return err
+	if err != nil {
+		return err
+	}
+	return disableWatchdog()
 }
 
 func installedCommandLine() (string, error) {