Add Android node foundation with FCM push support

src/gateway/server.test.ts

@@ -868,4 +868,56 @@ describe('GatewayServer node registration and capability negotiation', () => {
       }
     }
   });
+
+  it('supports android fcm push token registration', async () => {
+    if (!LISTEN_ALLOWED) {
+      return;
+    }
+
+    const ws = await new Promise<WebSocket>((resolve, reject) => {
+      const c = new WebSocket(`ws://127.0.0.1:${NODE_PORT}`);
+      c.on('open', () => resolve(c));
+      c.on('error', reject);
+    });
+
+    try {
+      const registered = await sendAndReceive(ws, {
+        id: 40,
+        method: 'node.register',
+        params: {
+          nodeId: 'node-android',
+          role: 'companion',
+          protocolVersion: 1,
+          capabilities: ['notifications'],
+        },
+      });
+      expect(((registered as GatewayResponse).result as { registered: boolean }).registered).toBe(true);
+
+      const push = await sendAndReceive(ws, {
+        id: 41,
+        method: 'node.push_token.set',
+        params: {
+          provider: 'fcm',
+          token: 'fcm_abcdefghijklmnopqrstuvwxyz123456',
+        },
+      });
+      expect(((push as GatewayResponse).result as { updated: boolean }).updated).toBe(true);
+
+      const nodes = await sendAndReceive(ws, {
+        id: 42,
+        method: 'system.nodes',
+        params: { role: 'companion', limit: 20 },
+      });
+      const list = ((nodes as GatewayResponse).result as {
+        nodes: Array<{ nodeId: string; push?: { provider: string; environment?: string } }>;
+      }).nodes;
+      const androidNode = list.find((entry) => entry.nodeId === 'node-android');
+      expect(androidNode?.push?.provider).toBe('fcm');
+      expect(androidNode?.push?.environment).toBeUndefined();
+    } finally {
+      if (ws.readyState === WebSocket.OPEN) {
+        ws.close();
+      }
+    }
+  });
 });