9router/omniroute reject all provider prefixes (openai/claude-* -> 404).
Model must be bare (claude-opus-5). litellm routes bare claude-* to the
Anthropic native provider, so we set ANTHROPIC_API_BASE/ANTHROPIC_API_KEY
env vars pointing at 9router instead of the OpenAI-shaped OPENAI__* env.
Bug: PR-Agent auto-review gagal karena model 'openai/claude-opus-4-8'
tidak valid di 9router (provider openai/ tidak ada).
Root cause: BWS secret pr_agent_pr_agent_model berisi prefix openai/
yang hanya valid untuk omniroute, bukan 9router. 9router pakai model
tanpa provider prefix (e.g. claude-opus-5).
Fix:
- Default CONFIG__MODEL: openai/claude-opus-5 -> claude-opus-5
- Fallback claude-sonnet-5 -> claude-sonnet-5 (drop openai/ prefix)
BWS secret juga sudah diupdate di production.