Credential revocation UX completed #201

Task #194 was completed and deployed. Credential revocation now requires confirmation, revoked OAuth credentials no longer show Reconnect, and expired-but-not-revoked OAuth credentials still can reconnect.

Implemented in src/ProjectMemory.Web/Components/Pages/Agents.razor and committed as bebc8d7 (Confirm agent credential revocation). The existing native dialog pattern is reused for the confirmation step. Published through scripts/Publish-Web.ps1 -Deploy; App_Data remained excluded.