v1.20.1 — Cloudflare Qwen structured response normalization
Fixes CloudflareProvider schema drift when Workers AI returns Qwen JSON output as a native object or array under response. Structured values are recursively validated as JSON and serialized to normalized text; string, numeric, choices[], output[], and Anthropic-via-CF response paths remain unchanged. Includes the live-captured Qwen Coder response fixture and exact AEGIS acceptance regression. Closes #104 via #105.