Add MiniMax and PinkCherry LTX as pickable video engines, with still or text start.

Shot 1 can run text-to-video; later shots still extend from the last frame. Recommend output is also normalized into shot-script cards.

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

server/utils/pending.ts

@@ -35,7 +35,7 @@ export interface PendingJob {
   referenceImageNames?: string[]
   referenceStillIds?: Array<string | null>
   useIdentityRefs?: boolean
-  workflow?: 'v1' | 'v2'
+  workflow?: import('~/utils/videoModels').VideoWorkflowId
   duration?: number
   cfg?: number
   fps?: number