Keep uploaded stills in the input picker and generated work in the library, and run image-edit passes as a chain like video extensions.

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

server/api/library/stills.post.ts

@@ -31,7 +31,8 @@ export default defineEventHandler(async (event) => {
     data: image.data,
     width: Number(fields.width || 0),
     height: Number(fields.height || 0),
-    hideInput: fields.hideInput === 'true'
+    hideInput: fields.hideInput === 'true',
+    role: 'input'
   })
   return { still: still || undefined, ...publicLibrary(event) }
 })