[Bug]: wrong replay_status in edge cases

[zhongkechen]

Expected Behavior

replay_status is always set to NEW OR REPLAY properly

Actual Behavior

In case initial_execution_state comes with one execution operation and other operations come in next pages, re-invocation of the execution will start mistakenly in NEW mode.

https://github.com/aws/aws-durable-execution-sdk-python/blob/main/src/aws_durable_execution_sdk_python/execution.py#L259

Steps to Reproduce

N/A

SDK Version

1.4

Python Version

3.14

Is this a regression?

No

Last Working Version

No response

Additional Context

No response