6a3de3a89c
Implement Google RetryInfo.retryDelay support for handling 429 rate limit errors. Retries same model up to 3 times using exact delays from Google's API before trying fallback models. - Add parseRetryDelay() to extract Google's retry guidance - Implement inner retry loop in Execute() and ExecuteStream() - Context-aware waiting with cancellation support - Cap delays at 60s maximum for safety