Show rosidl buffer backend metadata in topic endpoint info

[nvcyc]

Description

Expose rosidl buffer backend metadata in rclpy.TopicEndpointInfo and include it in the string representation used by verbose topic introspection.

With the matching RMW/RMW implementation changes, ros2 topic info <topic> -v can now show buffer backend support for publishers and subscriptions.

Is this user-facing behavior change?

Yes. ros2 topic info <topic> -v can display a Buffer backends: <backends> line for each topic endpoint.

Did you use Generative AI?

Yes. GPT-5.5 in Cursor was used to help draft changes in this pull request.

Additional Information

Depending on:

• Add rosidl buffer backend metadata to topic endpoint info rmw#419

Relevant but not directly dependent:

• Store rosidl buffer backend metadata in graph cache rmw_dds_common#88
• Expose discovered rosidle buffer backends through graph cache rmw_fastrtps#889

[fujitatomoya]

lgtm

probably it would be nice to show this platform buffer info with ros2cli ros2 topic info -v.

[fujitatomoya]

lgtm

probably it would be nice to show this platform buffer info with ros2cli ros2 topic info -v.

ros2/ros2cli#1245