fix(auto-update): proxy update execution to remote nodes via Distributed API (#419)

* fix(auto-update): proxy update execution to remote nodes via Distributed API

Remote auto-update policies previously failed because the scheduler tried
to access the Docker daemon directly on remote nodes. Now the scheduler
detects remote nodes and proxies the update execution via HTTP to the
remote Sencho instance's new /api/auto-update/execute endpoint, which
runs image checks and compose updates locally on the remote machine.

* test(auto-update): add getNode mock to NodeRegistry in scheduler tests

The executeUpdate method now calls NodeRegistry.getNode() to detect
remote nodes. The test mock for NodeRegistry was missing this method,
causing the two executeUpdate tests to fail.

backend/src/index.ts

@@ -5412,6 +5412,103 @@ app.get('/api/image-updates/fleet', authMiddleware, async (_req: Request, res: R
   }
 });
 
+// =========================
+// Auto-Update Execution API
+// =========================
+
+// Execute auto-update for a single stack (or all stacks with target "*").
+// This runs locally on whichever Sencho instance receives the request.
+// The gateway scheduler proxies this to remote nodes via HTTP.
+app.post('/api/auto-update/execute', authMiddleware, async (req: Request, res: Response) => {
+  if (!requireAdmin(req, res)) return;
+  try {
+    const { target } = req.body as { target?: string };
+    if (!target || typeof target !== 'string') {
+      return res.status(400).json({ error: 'Missing "target" (stack name or "*" for all)' });
+    }
+
+    let stackNames: string[];
+    if (target === '*') {
+      stackNames = await FileSystemService.getInstance(req.nodeId).getStacks();
+      if (stackNames.length === 0) {
+        return res.json({ result: 'No stacks found on node; skipped.' });
+      }
+    } else {
+      if (!isValidStackName(target)) {
+        return res.status(400).json({ error: 'Invalid stack name' });
+      }
+      stackNames = [target];
+    }
+
+    const docker = DockerController.getInstance(req.nodeId);
+    const imageUpdateService = ImageUpdateService.getInstance();
+    const compose = ComposeService.getInstance(req.nodeId);
+    const db = DatabaseService.getInstance();
+    const atomic = LicenseService.getInstance().getTier() === 'paid';
+    const results: string[] = [];
+
+    for (const stackName of stackNames) {
+      try {
+        const containers = await docker.getContainersByStack(stackName);
+        if (!containers || containers.length === 0) {
+          results.push(`Stack "${stackName}": no containers found; skipped.`);
+          continue;
+        }
+
+        const imageRefs = [...new Set(
+          containers
+            .map((c: { Image?: string }) => c.Image)
+            .filter((img): img is string => !!img && !img.startsWith('sha256:'))
+        )];
+
+        if (imageRefs.length === 0) {
+          results.push(`Stack "${stackName}": no pullable images; skipped.`);
+          continue;
+        }
+
+        let hasUpdate = false;
+        const updatedImages: string[] = [];
+        for (const imageRef of imageRefs) {
+          try {
+            if (await imageUpdateService.checkImage(docker, imageRef)) {
+              hasUpdate = true;
+              updatedImages.push(imageRef);
+            }
+          } catch (e) {
+            console.warn(`[AutoUpdate] Failed to check image ${imageRef}:`, e);
+          }
+        }
+
+        if (!hasUpdate) {
+          results.push(`Stack "${stackName}": all images up to date.`);
+          continue;
+        }
+
+        await compose.updateStack(stackName, undefined, atomic);
+        db.clearStackUpdateStatus(req.nodeId, stackName);
+
+        NotificationService.getInstance().dispatchAlert(
+          'info',
+          `Auto-update: stack "${stackName}" updated with new images`,
+          stackName
+        );
+
+        results.push(`Stack "${stackName}": updated (${updatedImages.join(', ')}).`);
+      } catch (e) {
+        const msg = e instanceof Error ? e.message : String(e);
+        results.push(`Stack "${stackName}" failed: ${msg}`);
+        console.error(`[AutoUpdate] Failed for stack "${stackName}":`, e);
+      }
+    }
+
+    res.json({ result: results.join('\n') });
+  } catch (error) {
+    const msg = error instanceof Error ? error.message : 'Auto-update execution failed';
+    console.error('[AutoUpdate] Execute error:', msg);
+    res.status(500).json({ error: msg });
+  }
+});
+
 // =========================
 // Node Management API
 // =========================