docs: update overview and sample config

README.md

@@ -4,13 +4,40 @@
 
 # trx-rs (work in progress)
 
-This is an early, untested snapshot of a transceiver control stack (core + backend + HTTP frontend). Things may change quickly and APIs are not stable yet. Expect rough edges and bugs; use at your own risk and please report issues you hit. Features, tests and docs are still being written (or not).
+This is an early, untested snapshot of a transceiver control stack (core + backend + frontends). Things may change quickly and APIs are not stable yet. Expect rough edges and bugs; use at your own risk and please report issues you hit. Features, tests and docs are still being written (or not).
+
+The rig task is now driven by the controller components (state machine, handlers, and policies). Polling and retry behavior are configurable via the `[behavior]` section in the config file.
 
 ## Supported backends
 
 - Yaesu FT-817 (feature-gated crate `trx-backend-ft817`)
 - Planned: other rigs I own; contributions and reports are welcome.
 
+## Frontends
+
+- HTTP status/control frontend (`trx-frontend-http`)
+- JSON TCP control frontend (`trx-frontend-http-json`)
+- Qt/QML GUI frontend (`trx-frontend-qt`, Linux only, optional via `qt-frontend` feature)
+- rigctl-compatible TCP frontend (`trx-frontend-rigctl`, listens on 127.0.0.1:4532)
+
+## Plugin discovery
+
+`trx-bin` can load shared-library plugins that register backends/frontends via a
+`trx_register` entrypoint. Search paths:
+
+- `./plugins`
+- `~/.config/trx-rs/plugins`
+- `TRX_PLUGIN_DIRS` (path-separated)
+
+Example plugin: `examples/trx-plugin-example`
+
+## Qt remote client
+
+The Qt frontend can run as a remote client over the JSON TCP interface.
+Configure the server with `frontends.http_json.auth.tokens` and the client with
+`frontends.qt.remote.enabled`, `frontends.qt.remote.url`, and
+`frontends.qt.remote.auth.token`.
+
 ## License
 
 This project is licensed under the BSD-2-Clause license. See `LICENSES/` for bundled third-party license files.