Adds `llm.thinking` config option (default: true) that when disabled: - Injects /no_think into the last user message for Qwen 3.x compatibility - Sends chat_template_kwargs in API payload for backends that support it - Silently and immediately nudges on reasoning-only responses instead of showing warnings and wasting retry iterations Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>