feat(webui): add tabbed pane workbench (#5322)

nanobot/channels/websocket/runtime.py

@@ -530,6 +530,10 @@ class WebSocketChannel(BaseChannel):
         except Exception as e:
             self.logger.warning("failed to send {} event: {}", event, e)
 
+    async def _broadcast_webui_event(self, event: str, **fields: Any) -> None:
+        for connection in tuple(self._webui_connections):
+            await self._send_event(connection, event, **fields)
+
     @classmethod
     def default_config(cls) -> dict[str, Any]:
         return WebSocketConfig().model_dump(by_alias=True)
@@ -848,7 +852,7 @@ class WebSocketChannel(BaseChannel):
                 )
                 return
             try:
-                await asyncio.to_thread(
+                saved_state = await asyncio.to_thread(
                     write_webui_sidebar_state,
                     cast(dict[str, Any], state),
                 )
@@ -858,6 +862,11 @@ class WebSocketChannel(BaseChannel):
                     "error",
                     detail="invalid_sidebar_state",
                 )
+                return
+            await self._broadcast_webui_event(
+                "sidebar_state_updated",
+                state=saved_state,
+            )
             return
         if t == "set_workspace_scope":
             cid = envelope.get("chat_id")
@@ -1207,6 +1216,11 @@ class WebSocketChannel(BaseChannel):
                         message="WebUI mutation returned an invalid response",
                     )
                     return
+                if action == "sidebar.update" and isinstance(result, dict):
+                    await self._broadcast_webui_event(
+                        "sidebar_state_updated",
+                        state=result,
+                    )
                 await self._send_webui_response(
                     connection,
                     request_id,

nanobot/channels/websocket/tests/test_websocket_channel.py

@@ -1037,6 +1037,63 @@ async def test_webui_persists_sidebar_state_larger_than_http_request_line(
     }
 
 
+@pytest.mark.asyncio
+async def test_webui_sidebar_state_update_broadcasts_workbench_to_other_devices(
+    bus: MagicMock,
+    tmp_path: Path,
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setattr("nanobot.config.paths.get_data_dir", lambda: tmp_path)
+    channel = _ch(bus)
+    source = AsyncMock()
+    source.request = SimpleNamespace(headers=Headers())
+    other_device = AsyncMock()
+    channel._webui_connections.update({source, other_device})
+    request_id = "sidebar-workbench-state"
+
+    await channel._dispatch_envelope(
+        source,
+        "webui-client",
+        {
+            "type": "webui_request",
+            "request_id": request_id,
+            "action": "sidebar.update",
+            "payload": {
+                "state": {
+                    "workbench": {
+                        "version": 1,
+                        "tabs": {
+                            "tab:websocket:a": {
+                                "explicit": True,
+                                "title": "Research",
+                                "paneKeys": ["websocket:a", "websocket:b"],
+                                "layoutPaneKeys": ["websocket:b", "websocket:a"],
+                                "layout": "columns",
+                                "splitRatios": [0.35],
+                            }
+                        },
+                    }
+                }
+            },
+        },
+    )
+    await asyncio.gather(*tuple(channel._webui_request_tasks.values()))
+
+    event = json.loads(other_device.send.await_args.args[0])
+    assert event["event"] == "sidebar_state_updated"
+    assert event["state"]["workbench"]["tabs"]["tab:websocket:a"]["paneKeys"] == [
+        "websocket:a",
+        "websocket:b",
+    ]
+    assert event["state"]["workbench"]["tabs"]["tab:websocket:a"]["layoutPaneKeys"] == [
+        "websocket:b",
+        "websocket:a",
+    ]
+    assert event["state"]["workbench"]["tabs"]["tab:websocket:a"]["splitRatios"] == [
+        0.35
+    ]
+
+
 @pytest.mark.asyncio
 async def test_client_cannot_self_assert_webui_quote_context(bus: MagicMock) -> None:
     channel = _ch(bus)