chore(release): v1.0.0-rc.4

[agentcore-devx-automation]

Merging publishes @aws/agentcore@1.0.0-rc.4 to npm and creates the v1.0.0-rc.4 GitHub release with generated notes.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.25%. Comparing base (484fdde) to head (c4cd504).
⚠️ Report is 5 commits behind head on refactor.

Additional details and impacted files

@@            Coverage Diff            @@
##           refactor    #2391   +/-   ##
=========================================
  Coverage     97.25%   97.25%           
=========================================
  Files           613      613           
  Lines         41028    41028           
=========================================
  Hits          39902    39902           
  Misses         1126     1126           

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[github-actions]

Thanks for the report, @codecov-commenter — feedback like this is exactly
how we catch the things we missed. Because this PR is already
closed, the team won't see follow-up comments here.

Would you mind opening a new issue so we can track it properly?
https://github.com/aws/agentcore-cli/issues/new/choose

If this is a security issue, please report it privately via
https://aws.amazon.com/security/vulnerability-reporting/ instead
of a public issue.