Detect OpenAI "no credits" 429 as exhausted balance

A real API call returned 429 "You have no credits remaining" without the
word "quota", so the UI wrongly said the AI was busy. Match quota,
credit and billing wording; test uses the real message.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

recipes/ai.py

@@ -237,8 +237,9 @@ def map_api_error(error):
     if isinstance(error, openai.APITimeoutError):
         return AIError("Die KI hat zu lange gebraucht. Bitte versuche es gleich noch einmal.")
     if isinstance(error, openai.RateLimitError):
-        code = getattr(error, "code", None) or ""
-        if "quota" in str(code) or "quota" in str(error).lower():
+        # Out of credit is also a 429; OpenAI words it as "quota", "credits" or "billing".
+        details = f"{getattr(error, 'code', None) or ''} {error}".lower()
+        if any(word in details for word in ("quota", "credit", "billing")):
             return AIError("Das OpenAI-Guthaben ist aufgebraucht. Bitte den Admin informieren.")
         return AIError("Die KI ist gerade ausgelastet (Rate-Limit). Bitte in einer Minute erneut versuchen.")
     if isinstance(error, (openai.AuthenticationError, openai.PermissionDeniedError)):

tests/test_ai.py

@@ -108,6 +108,9 @@ def api_error(cls, status, message="error", body=None):
         (openai.APITimeoutError(request=REQUEST), "zu lange"),
         (api_error(openai.RateLimitError, 429, "Rate limit reached"), "ausgelastet"),
         (api_error(openai.RateLimitError, 429, "You exceeded your current quota", {"code": "insufficient_quota"}), "Guthaben"),
+        # Real-world message seen from the API (2026-10) for an account without credit
+        (api_error(openai.RateLimitError, 429, "Error code: 429 - You have no credits remaining. Add credits to "
+                   "continue using the API at https://platform.openai.com/settings/organization/billing/."), "Guthaben"),
         (api_error(openai.AuthenticationError, 401), "API-Key"),
         (api_error(openai.NotFoundError, 404), "OPENAI_MODEL"),
         (api_error(openai.BadRequestError, 400), "nicht verarbeiten"),