## Summary
Plugin loading and auth projection both previously produced
`PluginLoadOutcome`. That made an unfiltered load result look like
runtime-ready capabilities and generated capability summaries before
auth routing had run.
This change keeps loaded plugin records in the cache, applies the
current auth policy in `PluginsManager`, and only then builds
`PluginLoadOutcome` and its summaries. Auth changes still reuse the
cached disk load and re-resolve apps and MCP servers without reloading
plugins.
The updated tests cover cached auth changes and verify that capability
summaries match the effective app/MCP surface.
## Testing
- `just test -p codex-core-plugins`
- `just test -p codex-plugin`
- `just fix -p codex-core-plugins`