The UI now uses a SearchBackend abstraction that wraps either:
- CoreClient (daemon mode): connects to owlry-core via IPC for search,
frecency tracking, submenu queries, and plugin actions
- Local ProviderManager (dmenu mode): unchanged direct provider access
Key changes:
- New backend.rs with SearchBackend enum abstracting IPC vs local
- app.rs creates CoreClient in normal mode, falls back to local if
daemon unavailable
- main_window.rs uses SearchBackend instead of ProviderManager+FrecencyStore
- Command execution stays in the UI (daemon only tracks frecency)
- dmenu mode path is completely unchanged (no daemon involvement)
- Added terminal field to IPC ResultItem for proper terminal launch
- Added PluginAction IPC request for plugin command execution
Adds Server struct that listens on a Unix domain socket, accepts
client connections (thread-per-client), reads newline-delimited JSON
requests, dispatches to ProviderManager/FrecencyStore/Config, and
sends JSON responses back. Includes stale socket cleanup and Drop
impl for socket removal.
