## What changed
- Cache global, user, and workspace remote plugin catalogs on disk with a three-hour TTL and scope- and account-specific keys.
- Serve cached catalogs from `plugin/list`, refresh stale entries in the background, and warm existing caches at app-server startup without blocking list requests.
- Make `forceRefetch: true` bypass cached catalog data and replace an entry only after a successful fetch.
- Invalidate user and workspace catalog caches after remote plugin sharing changes.
## Testing
- Cover cache freshness, scope isolation, legacy global cache compatibility, identity requirements for private catalogs, forced refetches, and non-blocking startup refreshes.
GitOrigin-RevId: 7844e9dfb72e43b26d749b4afd16fd9c1793caba
83ff1c2f80