Do not mark a waiting I2V complete when the image job finishes.

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

server/api/generate.post.ts

@@ -201,6 +201,19 @@ export default defineEventHandler(async (event) => {
       hideInput
     })
     : null)
+  if (!textToVideo && !still?.id) {
+    throw createError({ statusCode: 400, statusMessage: 'An initial image is required' })
+  }
+  console.info('[aigen generate]', {
+    hasImage: Boolean(image?.data?.length),
+    imageBytes: image?.data?.length || 0,
+    imageName: image?.filename || '',
+    stillId: still?.id || '',
+    postedStillId,
+    workflow,
+    promptChars: promptRaw.length,
+    textToVideo
+  })
   const referenceStillIds: Array<string | null> = [null, null, null, null]
   if (useIdentityRefs) {
     for (const [index, ref] of referenceImages.entries()) {