[FEATURE] Show reasoning text in PrintingCallbackHandler

[awsarron]

Problem Statement

In PrintingCallbackHandler (https://github.com/strands-agents/sdk-python/blob/61c3bf794f81c46aef4cd40ded6a68b7b48acb20/src/strands/handlers/callback_handler.py#L7C7-L7C30) I would like reasoning text (extended thinking) to be printed for models that support it.

Proposed Solution

Modify the PrintingCallbackHandler to handle reasoningText events.

Example in agent-builder:
https://github.com/strands-agents/agent-builder/blob/d61eca45745f3573cfc321ef3a5df90637f01d2e/src/strands_agents_builder/handlers/callback_handler.py#L116-L117.

Use Case

Show reasoning text returned by models that support it.

Alternatives Solutions

No response

Additional Context

No response

[awsarron]

Resolving this as it was contributed in #109 by @josephgultekin.