Add clip extension from the last frame with FFmpeg stitching.

Let a finished player continue into a new MiniMax segment, then losslessly concat the parts and discard the intermediate files so the library keeps one extended MP4.

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

server/api/interrupt.post.ts

@@ -5,6 +5,7 @@ export default defineEventHandler(async (event) => {
   if (job) {
     job.status = 'cancelled'
     emitJob(job, { type: 'status', message: 'Cancelling job...' })
+    removeExtendTemp(job.library?.extendTmpDir)
   }
   if (jobId) deletePendingJob(jobId)
   const ok = await interruptComfy()