model-price-refresh

Audit every LLM provider's official pricing page against the model_prices table and ship the diff as a migration. Use this whenever the user asks whether our providers' models are up to date, mentions a specific model missing from cost tracking, reports cost_usd coming back null or looking wrong, asks to "refresh prices" / "check the latest models" / "add <model>", or when a scheduled price-refresh routine fires.…