- config.py: NEMOTRON_DIAGNOSE_TIMEOUT_SECONDS=60s (NIM 實測 11-45s + 15s buffer) - config.py: OLLAMA_DIAGNOSE_TIMEOUT_SECONDS=200s (Ollama 實測 ~173s + 27s buffer) - ollama.py: 新增 per-task timeout (diagnose/force_local 用 200s) - ai_router.py: _local_fallback_chain 移除 Nemotron (NIM=雲端,不可進 local chain) - ai_router.py: v4.2 — Option C 分情境路由正式確立 Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>