Spell out which Coolify backup vars belong on AIGen vs xAIGen.

A URL in BACKUP_INGEST_TOKEN was treated as a missing token. Errors now say to put the URL on AIGen and the same secret on both apps.

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

server/api/library/stills/[id]/backup.post.ts

@@ -1,17 +1,17 @@
 import { readFileSync } from 'node:fs'
 import { isXaigenStudio } from '~/utils/videoModels'
+import { backupStudioConfigError, backupStudioTarget } from '~/server/utils/backupStudio'
 import { assertLibraryOwner, getStill, stillPath } from '~/server/utils/library'
 
 export default defineEventHandler(async (event) => {
   if (isXaigenStudio()) {
     throw createError({ statusCode: 404, statusMessage: 'Not found' })
   }
-  const config = useRuntimeConfig()
-  const url = String(config.backupStudioUrl || process.env.BACKUP_STUDIO_URL || '').replace(/\/$/, '')
-  const token = String(config.backupStudioToken || process.env.BACKUP_STUDIO_TOKEN || '').trim()
-  if (!url || !token) {
-    throw createError({ statusCode: 503, statusMessage: 'Backup studio is not configured' })
+  const missing = backupStudioConfigError()
+  if (missing) {
+    throw createError({ statusCode: 503, statusMessage: missing })
   }
+  const { url, token } = backupStudioTarget()
   const { owner } = assertLibraryOwner(event)
   const id = String(getRouterParam(event, 'id') || '')
   const still = getStill(owner, id)
@@ -31,7 +31,7 @@ export default defineEventHandler(async (event) => {
     const message = await res.text().catch(() => '')
     throw createError({
       statusCode: res.status === 401 ? 502 : res.status,
-      statusMessage: message || 'Backup studio refused the still'
+      statusMessage: message || 'xAIGen refused the still. Check BACKUP_INGEST_TOKEN matches AIGen BACKUP_STUDIO_TOKEN.'
     })
   }
   return { ok: true }