Stop ghost extension clips and recover last-frame extract after an interrupt.

Only one Comfy finish path can save a clip, hide catalog entries whose MP4 is missing, and retry last-frame extract so a truncated file does not dump FFmpeg noise into the UI.

Co-authored-by: Cursor <cursoragent@cursor.com>

server/utils/pending.ts

@@ -70,10 +70,42 @@ export function deletePendingJob(jobId: string) {
 }
 
 export async function completePendingIfReady(pending: PendingJob) {
+  const alreadySaved = () => {
+    const live = getJob(pending.jobId)
+    if (live?.savedPromptId === pending.promptId) {
+      deletePendingJob(pending.jobId)
+      return {
+        type: 'complete' as const,
+        status: 'complete' as const,
+        message: pending.folderLocked
+          ? 'Saved to the locked folder. Unlock it to view.'
+          : (pending.extendPart1Path ? 'Extended video ready' : 'Video ready'),
+        progress: 100,
+        jobId: pending.jobId,
+        clipId: live.clipId,
+        hideThumbnail: pending.hideThumbnail,
+        folderLocked: pending.folderLocked
+      }
+    }
+    return null
+  }
+  const inFlight = () => {
+    const current = getJob(pending.jobId)
+    return Boolean(current && current.promptId === pending.promptId && current.saving)
+  }
+  if (inFlight()) return null
+  const saved = alreadySaved()
+  if (saved) return saved
   const history = await fetchHistory(pending.promptId)
+  if (inFlight()) return null
+  const afterHistory = alreadySaved()
+  if (afterHistory) return afterHistory
   const video = extractVideo(history, pending.promptId)
   if (!video) return null
   let buffer = await downloadComfyVideo(video)
+  if (inFlight()) return null
+  const afterDownload = alreadySaved()
+  if (afterDownload) return afterDownload
   if (pending.extendPart1Path && pending.extendTmpDir) {
     if (!existsSync(pending.extendPart1Path)) {
       removeExtendTemp(pending.extendTmpDir)
@@ -91,6 +123,8 @@ export async function completePendingIfReady(pending: PendingJob) {
     }
     removeExtendTemp(pending.extendTmpDir)
   }
+  const afterStitch = alreadySaved()
+  if (afterStitch) return afterStitch
   const clip = await saveClip({
     ownerKey: pending.ownerKey,
     folderId: pending.folderId,