Keep the Extend panel put and name sibling clips as branches.

A finished job no longer closes a draft or jumps the page, and a second extend from the same part saves as p8b instead of another p8.

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

server/api/extend.post.ts

@@ -5,6 +5,7 @@ import { readLoraStack } from '~/utils/loras'
 import { parseExtendDuration } from '~/server/utils/extendChain'
 import { defaultVideoSteps, isLtxWorkflow, LTX_DISABLED_MESSAGE, ltxWorkflowEnabled, parseVideoWorkflow } from '~/utils/videoModels'
 import { composePromptParts } from '~/utils/promptParts'
+import { nextFamilyPartName } from '~/server/utils/library'
 
 export default defineEventHandler(async (event) => {
   const body = await readBody<{ clipId?: string; prompt?: string; promptPre?: string; promptPost?: string; duration?: number; lora?: unknown; loraStack?: unknown }>(event).catch(() => ({}))
@@ -45,6 +46,10 @@ export default defineEventHandler(async (event) => {
   const turbo = source.turbo !== false
   const steps = Number(source.steps || defaultVideoSteps(turbo, workflow))
   const seed = Math.floor(Math.random() * 2_147_483_647)
+  const reservedNames = listStudioJobs(owner)
+    .filter(job => job.status === 'waiting' || job.status === 'running' || job.status === 'held')
+    .map(job => job.name)
+    .filter(Boolean)
 
   const studio = await addStudioJob({
     ownerKey: owner,
@@ -54,7 +59,7 @@ export default defineEventHandler(async (event) => {
       promptMid: prompt,
       promptPre,
       promptPost,
-      name: nextClipPartName(clipTitle(source)),
+      name: nextFamilyPartName(owner, source, reservedNames),
       folderId: source.folderId,
       aspect: source.aspect || '16:9',
       width: source.width || 1344,
@@ -95,6 +100,7 @@ export default defineEventHandler(async (event) => {
     queued: !liveJobId,
     clientId: '',
     seed,
+    name: studio.name,
     width: source.width || 1344,
     height: source.height || 768,
     steps,