## Summary
- Allow remote installed-plugin cache refresh to start whenever plugins
are enabled.
- Allow remote installed-plugin bundle sync to start whenever plugins
are enabled.
- Remove the extra local `remote_plugin_enabled` guard from those
background sync paths.
## Context
Server-side installed plugin state and optional bundle URL behavior are
owned by plugin-service `/public/plugins/installed`, so these local sync
paths only need the overall plugin enablement gate.
## Test plan
- `just fmt`
- `cargo test -p codex-core-plugins`