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**Related issue:** Resolves#38234
This came up in activity bounded context code review.
Following existing patterns, authz testing will be in `policy_test.go`,
and integration tests will simply cover connectivity (not exhaustive
authz).
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## Summary by CodeRabbit
* **Tests**
* Enhanced authorization test coverage for activity operations with
improved validation scenarios.
<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>
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Victor Lyuboslavsky
ae1f846739