clarify agent identity for unpublished hosted agents

[paulbatum]

Currently, hosted agents that have not been published to applications run with the project managed identity, not an agent identity, so updating the docs to clarify.

[prmerger-automator]

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[learn-build-service-prod]

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[v-dirichards]

@aahill

Can you review the proposed changes?

Important: When the changes are ready for publication, adding a #sign-off comment is the best way to signal that the PR is ready for the review team to merge.

#label:"aq-pr-triaged"
@MicrosoftDocs/public-repo-pr-review-team

[Copilot]

Pull Request Overview

This PR clarifies the identity model for hosted agents by distinguishing between published and unpublished agent states. The update corrects a technical inaccuracy: unpublished agents use the project's managed identity, not an agent identity.

Key changes:

• Clarified that only published hosted agents receive a dedicated Agent Identity
• Updated terminology to accurately reflect that unpublished agents use the project's managed identity, not a "common agent identity"