fix: stop service and cleanup dirs before CDN script to handle old script versions

The CDN uninstall.sh is deployed separately and old versions still kill
all ggo processes. Move stopAgentService and cleanupDataDirs before the
CDN script so all critical work completes even if the process is killed.

Flow: unregister → stop service → cleanup dirs → CDN script

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: andystime

cmd/ggo/system/commands.go

@@ -112,7 +112,14 @@ func NewUninstallCmd() *cobra.Command {
 			// Step 1: Unregister agent from server (must happen before config is removed)
 			tryUnregisterAgent()
 
-			// Step 2: Run CDN uninstall script (stops service, removes service files and binary)
+			// Step 2: Stop agent service so it doesn't recreate files during shutdown
+			stopAgentService()
+
+			// Step 3: Clean up data directories (must complete before CDN script,
+			// because the old CDN script may kill this process)
+			cleanupDataDirs()
+
+			// Step 4: Run CDN uninstall script (removes service files and binary)
 			command, cmdArgs, err := buildScriptCommand(scriptActionUninstall, runtime.GOOS)
 			if err != nil {
 				return err
@@ -125,9 +132,6 @@ func NewUninstallCmd() *cobra.Command {
 				klog.Warningf("Uninstall script failed: %v", err)
 			}
 
-			// Step 3: Clean up data directories (after service is stopped by the script)
-			cleanupDataDirs()
-
 			return nil
 		},
 	}
@@ -193,6 +197,32 @@ func rootHomeDir() string {
 	return "/root"
 }
 
+// stopAgentService stops the ggo-agent system service so it doesn't recreate
+// files (e.g. workers.json) during shutdown while we're cleaning up directories.
+func stopAgentService() {
+	switch {
+	case platform.IsLinux():
+		cmd := exec.Command("sudo", "-n", "systemctl", "stop", "ggo-agent")
+		if os.Getuid() == 0 {
+			cmd = exec.Command("systemctl", "stop", "ggo-agent")
+		}
+		if err := cmd.Run(); err != nil {
+			klog.V(4).Infof("Could not stop ggo-agent service (may not exist): %v", err)
+		}
+	case platform.IsDarwin():
+		for _, plist := range []string{
+			filepath.Join(os.Getenv("HOME"), "Library", "LaunchAgents", "com.gpugo.agent.plist"),
+			"/Library/LaunchDaemons/com.gpugo.agent.plist",
+		} {
+			cmd := exec.Command("sudo", "-n", "launchctl", "unload", plist)
+			if os.Getuid() == 0 {
+				cmd = exec.Command("launchctl", "unload", plist)
+			}
+			_ = cmd.Run()
+		}
+	}
+}
+
 // tryUnregisterAgent attempts to unregister the agent from the server before cleanup.
 // It checks the current user's config first, then root's config on Unix systems
 // (since the agent typically runs as root via systemd/launchd).