Unify TUI runtime commands with gateway and harden gateway restart

src/frontends/tui/minimal.test.ts

@@ -403,7 +403,33 @@ describe('MinimalTui backend command', () => {
     }
   });
 
-  it('prints guidance when /runtime is invoked in TUI mode', async () => {
+  it('forwards /runtime command through runtime command callback', async () => {
+    const mockSession = {
+      id: 'test',
+      getHistory: () => [],
+      addMessage: vi.fn(),
+      clear: vi.fn(),
+      replaceHistory: vi.fn(),
+    };
+    const onRuntimeCommand = vi.fn(async () => 'Backend mode: config_default');
+    const logSpy = vi.spyOn(console, 'log').mockImplementation(() => {});
+    try {
+      const tui = new MinimalTui({
+        session: asSession(mockSession),
+        modelClient: asModelClient({}),
+        systemPrompt: 'test',
+        onRuntimeCommand,
+      });
+
+      await minimalTuiPrivates(tui).handleCommand({ type: 'runtime', input: 'status' });
+      expect(onRuntimeCommand).toHaveBeenCalledWith('status');
+      expect(logSpy).toHaveBeenCalledWith('Backend mode: config_default\n');
+    } finally {
+      logSpy.mockRestore();
+    }
+  });
+
+  it('prints guidance when runtime command service is unavailable', async () => {
     const mockSession = {
       id: 'test',
       getHistory: () => [],
@@ -420,7 +446,33 @@ describe('MinimalTui backend command', () => {
       });
 
       await minimalTuiPrivates(tui).handleCommand({ type: 'runtime', input: 'status' });
-      expect(logSpy).toHaveBeenCalledWith(expect.stringContaining('Runtime backend mode command is not available in this TUI mode.'));
+      expect(logSpy).toHaveBeenCalledWith(expect.stringContaining('Runtime backend mode command service is unavailable in this TUI session.'));
+    } finally {
+      logSpy.mockRestore();
+    }
+  });
+
+  it('keeps /backend status local-only and does not invoke runtime command callback', async () => {
+    const mockSession = {
+      id: 'test',
+      getHistory: () => [],
+      addMessage: vi.fn(),
+      clear: vi.fn(),
+      replaceHistory: vi.fn(),
+    };
+    const onRuntimeCommand = vi.fn(async () => 'should not be called');
+    const logSpy = vi.spyOn(console, 'log').mockImplementation(() => {});
+    try {
+      const tui = new MinimalTui({
+        session: asSession(mockSession),
+        modelClient: asModelClient({}),
+        systemPrompt: 'test',
+        onRuntimeCommand,
+      });
+
+      await minimalTuiPrivates(tui).handleCommand({ type: 'backend', provider: 'status' });
+      expect(onRuntimeCommand).not.toHaveBeenCalled();
+      expect(logSpy).toHaveBeenCalledWith(expect.stringContaining('Backend switching not available.'));
     } finally {
       logSpy.mockRestore();
     }