Unify TUI runtime commands with gateway and harden gateway restart

src/gateway/handlers/agent.test.ts

@@ -241,6 +241,67 @@ describe('createAgentHandlers command fast-path', () => {
     expect(((sent[0] as GatewayEvent).data as { content: string }).content).toContain('Cancellation requested');
   });
 
+  it('handles /runtime status via command fast-path without calling agent.process', async () => {
+    const sent: OutboundMessage[] = [];
+    const send = vi.fn((msg: OutboundMessage) => sent.push(msg));
+    const req: GatewayRequest = {
+      id: 13,
+      method: 'agent.send',
+      params: {
+        message: '/runtime status',
+        connectionId: 'conn-1',
+        metadata: { isCommand: true, command: 'runtime', commandArgs: 'status' },
+      },
+    };
+
+    await handlers['agent.send'](req, send);
+
+    expect(mockAgent.process).not.toHaveBeenCalled();
+    expect((sent[0] as GatewayEvent).event).toBe('done');
+    expect(((sent[0] as GatewayEvent).data as { content: string }).content).toContain('Backend mode:');
+  });
+
+  it('handles /runtime deactivate pi via shared backend mode service callbacks', async () => {
+    const sent: OutboundMessage[] = [];
+    const send = vi.fn((msg: OutboundMessage) => sent.push(msg));
+    let backendMode: 'config_default' | 'force_native' | 'force_pi_embedded' = 'force_pi_embedded';
+    const handlersWithBackendMode = createAgentHandlers({
+      sessionBridge: sessionBridge as unknown as AgentHandlerDeps['sessionBridge'],
+      laneQueue: new LaneQueue(),
+      sessionManager: sessionManager as unknown as AgentHandlerDeps['sessionManager'],
+      commandRegistry,
+      runtimeConfig: {
+        backends: {
+          default: 'pi_embedded',
+          claude_code: { enabled: false },
+          opencode: { enabled: false },
+          codex: { enabled: false },
+          gemini: { enabled: false },
+          pi_embedded: { enabled: true },
+        },
+      } as unknown as AgentHandlerDeps['runtimeConfig'],
+      getBackendMode: () => backendMode,
+      setBackendMode: (mode) => {
+        backendMode = mode;
+      },
+    });
+    const req: GatewayRequest = {
+      id: 14,
+      method: 'agent.send',
+      params: {
+        message: '/runtime deactivate pi',
+        connectionId: 'conn-1',
+        metadata: { isCommand: true, command: 'runtime', commandArgs: 'deactivate pi' },
+      },
+    };
+
+    await handlersWithBackendMode['agent.send'](req, send);
+
+    expect(mockAgent.process).not.toHaveBeenCalled();
+    expect(backendMode).toBe('force_native');
+    expect(((sent[0] as GatewayEvent).data as { content: string }).content).toContain('deactivated globally');
+  });
+
   it('falls through to agent.process for unknown commands', async () => {
     const sent: OutboundMessage[] = [];
     const send = vi.fn((msg: OutboundMessage) => sent.push(msg));