## Why
Renewed image URLs and other display metadata changes unnecessarily invalidate loaded plugins and MCP and skill caches, even when installed plugin behavior is unchanged.
## What changed
- Compare installed plugin metadata by identity, version, enablement, policy, and availability before invalidating derived caches. Continue storing the full updated payload so display consumers receive fresh metadata.
- Preserve invalidation when behavioral metadata changes or reconciliation requires an effective plugin refresh.
- Export `remote_catalog_metadata_eq` to compare catalogs independently of display metadata and plugin display order, while retaining marketplace order significance.
## Testing
Add regression tests for display-only updates, behavioral changes, catalog ordering, and preservation of loaded skills and tool suggestions. Add an app-server integration test verifying that image URL renewals and badge updates preserve live MCP sessions and cached skill resources, while an authentication policy change invalidates resource caches.
GitOrigin-RevId: 22b9ba1234a9f850201c6890e03d1ef899a56c54