Split prompts into pre/prompt/post and tidy the AIGen video form.

Keep wrappers off the library mid-prompt so Use as input and Extend restore the same split, send stills to xAIGen as hidden inputs, and stop the two-column library from growing with the list.

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

server/utils/studioQueue.ts

@@ -14,6 +14,9 @@ export type StudioJobKind = 'video' | 'edit'
 
 export interface StudioJobPayload {
   prompt: string
+  promptMid?: string
+  promptPre?: string
+  promptPost?: string
   name: string
   folderId: string
   aspect: string
@@ -942,6 +945,9 @@ export async function startStudioJob(item: StudioJob) {
     folderLocked: payload.folderLocked,
     name: payload.name,
     prompt: payload.prompt,
+    promptMid: payload.promptMid,
+    promptPre: payload.promptPre,
+    promptPost: payload.promptPost,
     aspect: payload.aspect,
     width: payload.width,
     height: payload.height,