fix(python): make retries safe and deterministic

AGENTS.md

@@ -48,6 +48,9 @@ This repository publishes the open-source server, console, integration catalog,
 - Keep functions focused on one ownership boundary.
 - Propagate unexpected errors to the CLI or request boundary.
 - Keep technical claims executable through tests or generated validation.
+- Interpret Python SDK `max_retries` as retries after the initial attempt and reject negative or non-integer values.
+- Retry RFC-idempotent Python SDK requests automatically; retry non-idempotent requests only when the transport proves the request was never sent.
+- Honor valid `Retry-After` delay-seconds and HTTP-date values, and release retryable responses before sleeping.
 - Avoid compatibility shims without a named public contract.
 - Preserve the minimum runtime versions declared by each package.