Extract _bad_request() so the five 400 branches don't duplicate the literal. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Extract _bad_request() so the five 400 branches don't duplicate the literal. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>