Show namespace capabilities in operator namespace describe text output

[vjymisal0]

Related issues

Closes #618

What changed?

temporal operator namespace describe (and namespace list) in text mode now includes a NamespaceInfo.Capabilities row. Previously capabilities were only visible with -o json, since JSON dumps the whole response but the text view uses a fixed field list.

The value is rendered the same way as the other nested proto fields in this view (e.g. ReplicationConfig.Clusters), as compact proto JSON. JSON output is unchanged.

Checklist

Stability

• Changes to JSON output (-o json / -o jsonl) are treated as breaking changes (JSON output is not changed)

Design

• This feature does not depend on Cloud-only APIs or behavior (it works against an OSS server)

Behavior

• Results go to stdout; errors and warnings go to stderr

Tests

• Added functional test(s) (SharedServerSuite): extended TestOperator_NamespaceCreateListAndDescribe to check the text output contains the capabilities row

Manual tests

Setup

temporal server start-dev --headless

Happy path

$ temporal operator namespace describe \
    --namespace default
  NamespaceInfo.Name                    default
  NamespaceInfo.Id                      01a0fd04-653a-7b07-8b4e-629b428df39b
  NamespaceInfo.Description
  NamespaceInfo.OwnerEmail
  NamespaceInfo.State                   Registered
  NamespaceInfo.Data                    map[]
  NamespaceInfo.Capabilities            {"eagerWorkflowStart":true,"syncUpdate":true,"asyncUpdate":true,"workerHeartbeats":true,"reportedProblemsSearchAttribute":true,"standaloneActivities":true,"pollerAutoscaling":true,"standaloneNexusOperation":true,"standaloneActivityStartDelay":true,"standaloneActivityBatchOperations":true,"standaloneActivityOperatorCommands":true}
  Config.WorkflowExecutionRetentionTtl  24h0m0s
  ...

temporal operator namespace list shows the same row for each namespace.

[CLAassistant]

All committers have signed the CLA.

[chaptersix]

happy to approve once you sign the cla @vjymisal0
Thank you!

[vjymisal0]

Thanks @chaptersix! The CLA is signed now and the license/cla check is green, so this should be ready for another look whenever you have a moment.