Add macOS companion node status and system.nodes APIs

docs/api/PROTOCOL.md

@@ -647,6 +647,26 @@ Requires `server.nodes.enabled: true` and `server.nodes.location.enabled: true`.
 
 Return the stored last-known location for the currently registered node connection.
 
+#### `node.status.set`
+
+Publish companion/node runtime status metadata (for example macOS menu-bar heartbeat state).
+
+**Request:**
+```json
+{
+  "id": 12,
+  "method": "node.status.set",
+  "params": {
+    "platform": "macos",
+    "appVersion": "0.3.1",
+    "deviceName": "MacBook Pro",
+    "statusText": "Idle",
+    "batteryPct": 64,
+    "powerSource": "battery"
+  }
+}
+```
+
 #### `system.capabilities`
 
 Return gateway protocol version, node policy status, and feature-gate snapshot.
@@ -684,6 +704,10 @@ Return gateway protocol version, node policy status, and feature-gate snapshot.
 
 Return the operator-facing snapshot of registered node locations.
 
+#### `system.nodes`
+
+Return the operator-facing snapshot of registered node connections (identity, role, capabilities, location/status).
+
 ### Canvas Methods
 
 #### `canvas.put`