fix(preview): add 60-second grace period before marking freshly booted servers as zombies to prevent aggressive 502 teardowns

vibn-frontend/app/[workspace]/project/[projectId]/(home)/preview/page.tsx

@@ -126,6 +126,7 @@ export default function PreviewTab() {
     if (primaryRunning || primaryStarting) return; // already up or already starting
 
     ensureCalledRef.current = true;
+    setEnsureStatus("calling");
 
     fetch(`/api/projects/${projectId}/dev-server/ensure`, {
       method: "POST",
@@ -144,7 +145,14 @@ export default function PreviewTab() {
         }
       })
       .catch(() => setEnsureStatus("error"));
-  }, [loading, anatomy, primaryRunning, primaryStarting, projectId]);
+  }, [
+    loading,
+    anatomy,
+    primaryRunning,
+    primaryStarting,
+    projectId,
+    refreshKey,
+  ]);
 
   const [iframeSrc, setIframeSrc] = useState<string | null>(null);
   const iframeDomRef = useRef<HTMLIFrameElement | null>(null);

vibn-frontend/app/api/projects/[projectId]/anatomy/route.ts

@@ -825,6 +825,14 @@ async function loadPreviews(projectId: string): Promise<Preview[]> {
             ping.status === 504 ||
             ping.status === 404
           ) {
+            // Give freshly booted servers a 60-second grace period before murdering them.
+            // Traefik sometimes returns 502 for a few seconds right after the internal probe succeeds.
+            const ageMs = Date.now() - new Date(r.started_at).getTime();
+            if (ageMs < 60000) {
+              activePreviews.push(r);
+              return;
+            }
+
             console.warn(
               `[anatomy] Preview zombie detected for ${r.preview_url} (HTTP ${ping.status}). Marking stopped.`,
             );