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/pending.ts

@@ -14,6 +14,8 @@ export interface PendingJob {
   folderLocked?: boolean
   name?: string
   prompt: string
+  promptPre?: string
+  promptPost?: string
   aspect: string
   width: number
   height: number
@@ -107,6 +109,8 @@ export function pendingFromJob(job: Job, overrides: Partial<PendingJob> = {}): P
     folderLocked: library.folderLocked,
     name: library.name,
     prompt: library.prompt,
+    promptPre: library.promptPre,
+    promptPost: library.promptPost,
     aspect: library.aspect,
     width: library.width,
     height: library.height,
@@ -164,6 +168,8 @@ export function libraryFromPending(pending: PendingJob): NonNullable<Job['librar
     folderLocked: pending.folderLocked,
     name: pending.name,
     prompt: pending.prompt,
+    promptPre: pending.promptPre,
+    promptPost: pending.promptPost,
     aspect: pending.aspect,
     width: pending.width,
     height: pending.height,
@@ -313,6 +319,8 @@ export async function completePendingIfReady(pending: PendingJob) {
     folderId: pending.folderId,
     name: pending.name,
     prompt: pending.prompt,
+    promptPre: pending.promptPre,
+    promptPost: pending.promptPost,
     aspect: pending.aspect,
     width: pending.width,
     height: pending.height,