## What changed
- Include remote catalog entries in `codex plugin list`, including their source,
version, install policy, and authentication policy in JSON output.
- Support adding and removing remote plugins through the existing plugin CLI.
- Cache remote catalogs by scope and collection. Prefer fresh cached results, and
refetch once when an add request misses a plugin in the cache.
- Preserve the local curated catalog when an unfiltered remote listing fails,
while surfacing errors for explicitly selected remote marketplaces.
## Testing
- Cover remote listing, installation, removal, catalog fallback, cache refresh,
collection isolation, and install failure behavior.
GitOrigin-RevId: 09796b2c393d102e00ba9289f784d78a2e166a54
6b59cefcbb