fix(app-store): handle orphaned stack directories on template deploy (#530)

* fix(app-store): handle orphaned stack directories on template deploy

When a stack deployed via the App Store is later removed through Docker
Desktop or the CLI (instead of through Sencho), its directory remains on
disk without a compose file. The deploy endpoint previously rejected any
re-deploy with a 409 if the directory existed, even if empty.

Now the endpoint checks for a compose file before rejecting. If the
directory exists but contains no compose file, it is treated as an
orphaned remnant: cleaned up automatically and the deploy proceeds.

Also makes FileSystemService.hasComposeFile public so the deploy
endpoint can reuse it instead of duplicating the compose file check.

* docs(app-store): document orphaned stack directory cleanup behavior

backend/src/index.ts

@@ -5687,10 +5687,17 @@ app.post('/api/templates/deploy', authMiddleware, async (req: Request, res: Resp
 
     try {
       await fsPromises.access(stackPath);
-      return res.status(409).json({
-        error: `A stack directory named '${stackName}' already exists. Please choose a different Stack Name.`,
-        rolledBack: false
-      });
+
+      if (await fsService.hasComposeFile(stackPath)) {
+        return res.status(409).json({
+          error: `A stack directory named '${stackName}' already exists. Please choose a different Stack Name.`,
+          rolledBack: false
+        });
+      }
+
+      // Orphaned directory left by external deletion (e.g. Docker Desktop).
+      console.log(`[Templates] Cleaned up orphaned stack directory: ${stackName}`);
+      await fsService.deleteStack(stackName);
     } catch {
       // Directory does not exist; proceed with deploy
     }

backend/src/services/FileSystemService.ts

@@ -34,7 +34,7 @@ export class FileSystemService {
     return new FileSystemService(nodeId);
   }
 
-  private async hasComposeFile(dir: string): Promise<boolean> {
+  async hasComposeFile(dir: string): Promise<boolean> {
     const composeFiles = ['compose.yaml', 'compose.yml', 'docker-compose.yaml', 'docker-compose.yml'];
     for (const file of composeFiles) {
       try {