DefaultTaskBridgeFailureClassifier

Default implementation of TaskBridgeFailureClassifier.

Retries on network IO errors, HTTP 429 (Too Many Requests), and HTTP 5xx (Server Errors).

Note: HTTP 401 (Unauthorized) is NOT classified as retryable here by default. The transport layer performs its own limited retries for 401 to allow for transient token refresh issues, but will eventually treat it as a fatal error.