## Context
The installed-app suggestion expansion added in #24996 reads plugin
details for trusted file-backed marketplace candidates because the list
response does not include app ids. On Windows-backed WSL mounts, the
local `openai-curated` checkout lives under `$CODEX_HOME/.tmp/plugins`,
and those per-plugin detail reads can be very slow.
Remote curated already has cached app ids, so it does not need the same
local filesystem traversal.
## Summary
- Keep only the WSL Windows-backed local `openai-curated` checkout on
the legacy fallback/configured discovery path.
- Preserve installed-app expansion for non-WSL file-backed marketplaces
and remote curated.
- Add focused tests for the WSL local curated path predicate.
## Test
- `just test -p codex-core-plugins discoverable`
- `just test -p codex-core plugins::discoverable::tests`
## Summary
- Move plugin discoverable recommendation filtering from `codex-core`
into `codex-core-plugins` behind `ToolSuggestPluginDiscoveryInput`.
- Keep `codex-core` as a thin adapter from `Config` to the core-plugins
API and back to `DiscoverablePluginInfo`.
- Keep the existing discoverable allowlist private to the core-plugins
implementation.
## Validation
- `just fmt`
- `just test -p codex-core list_tool_suggest_discoverable_plugins`
- `git diff --check`
- Read-only subagent review: no findings
xl-openai