Add runtime networking APIs

docs/protocol.md

@@ -73,6 +73,25 @@ Image-capable nodes may also use nine-slice scaling with source-pixel insets:
 
 Nine-slice keeps corners unscaled, stretches edges on one axis, and stretches the center on both axes. Insets are clamped to the selected source region and destination size.
 
+## Runtime network API
+
+Lua may use runtime-owned async networking without blocking script execution:
+
+- `runtime.http_request({ id?, method?, url, headers?, body?, timeout? })`
+- `runtime.ws_connect({ id?, url, protocols? })`
+- `runtime.ws_send(id, message)`
+- `runtime.ws_close(id)`
+
+HTTP requests support `http` and `https` URLs. WebSocket connections support `ws` and `wss` URLs.
+
+Network results are delivered back to Lua through `on_event(event)`:
+
+- `network_http`: HTTP request completed or failed. `event.data` includes `id`, `url`, `method`, `ok`, and either `status`/`headers`/`body` or `error`.
+- `network_ws_open`: WebSocket connection opened.
+- `network_ws_message`: WebSocket message received.
+- `network_ws_error`: WebSocket connection or stream error.
+- `network_ws_close`: WebSocket connection closed.
+
 ## RuntimeCommand
 
 Runtime commands request generic side effects owned by Dart/Flame.