#14553: feat(llm): Add automatic retry mechanism for TPM/RPM rate limits

### Summary Add automatic retry mechanism for LLM API calls with exponential backoff to handle TPM/RPM rate limit errors. Changes: - Add retry config support in models.providers[].retry - Add TPM-specific error patterns detection (tpm limit, tokens per minute, etc.) - Create prompt-retry.ts utility with configurable retry: - Default 10 attempts - Exponential backoff with jitter - Auto retry_after parsing from error response - Wrap activeSession.prompt() calls with retry wrapper ### Config example: ```yaml models: providers: openai: retry: attempts: 10 minDelayMs: 1000 maxDelayMs: 60000 jitter: 0.2 ``` ### Retryable errors: - TPM/RPM rate limits - 429 Too Many Requests - Quota exceeded - Resource exhausted ### Non-retryable: - Authentication errors - Context overflow - Validation errors <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> This change introduces a retry wrapper around `activeSession.prompt()` in the embedded runner to automatically retry on rate-limit style failures (TPM/RPM/429/quota/resource exhausted), using `retryAsync`’s exponential backoff with jitter. It also adds an optional per-provider retry config (`models.providers.<provider>.retry`) to the config types and Zod schema, and expands rate-limit error pattern matching to include TPM phrasing. <h3>Confidence Score: 5/5</h3> - This PR appears safe to merge; changes are localized and align with existing retry infrastructure. - I reviewed all changed files and verified the new module import patterns match existing repo conventions (TS sources importing .js specifiers), the config schema/type additions are consistent, and the retry wrapper delegates to the existing `retryAsync` implementation without altering core request logic beyond adding retries on clearly rate-limit-related errors. - No files require special attention <!-- greptile_other_comments_section --> _{(2/5) Greptile learns from your feedback when you react with thumbs up/down!} <!-- /greptile_comment -->