Silence console warnings in frontend tests

Suppress expected console output during tests:
- layout.test.tsx: DOM nesting warnings (html in div) expected when testing Next.js RootLayout
- useInteractiveTerminal.test.tsx: terminal initialization logs
- useTerminalModalState.test.tsx: fallback mode warnings

https://claude.ai/code/session_014uQFZGsQRXtUAcxgzDkSaW

frontend/app/__tests__/layout.test.tsx

@@ -2,6 +2,24 @@ import React from 'react';
 import { render, screen } from '@testing-library/react';
 import RootLayout, { metadata } from '../layout';
 
+// Suppress console.error for DOM nesting warnings in tests
+// (html cannot be child of div - expected when testing Next.js RootLayout)
+const originalConsoleError = console.error;
+beforeAll(() => {
+  console.error = jest.fn((...args) => {
+    const message = args.map(arg => String(arg)).join(' ');
+    // Suppress DOM nesting warnings that occur when testing RootLayout
+    if (message.includes('cannot be a child of') || message.includes('hydration error')) {
+      return;
+    }
+    originalConsoleError.apply(console, args);
+  });
+});
+
+afterAll(() => {
+  console.error = originalConsoleError;
+});
+
 // Mock the ThemeProvider and Providers
 jest.mock('@/lib/theme', () => ({
   ThemeProvider: ({ children }: { children: React.ReactNode }) => <div data-testid="theme-provider">{children}</div>,

frontend/lib/hooks/__tests__/useInteractiveTerminal.test.tsx

@@ -1,6 +1,23 @@
 import { renderHook, act } from '@testing-library/react';
 import { useInteractiveTerminal } from '../useInteractiveTerminal';
 
+// Suppress console output during tests (terminal initialization logs)
+const originalConsoleLog = console.log;
+const originalConsoleWarn = console.warn;
+const originalConsoleError = console.error;
+
+beforeAll(() => {
+  console.log = jest.fn();
+  console.warn = jest.fn();
+  console.error = jest.fn();
+});
+
+afterAll(() => {
+  console.log = originalConsoleLog;
+  console.warn = originalConsoleWarn;
+  console.error = originalConsoleError;
+});
+
 // Mock socket.io-client
 const mockSocket = {
   on: jest.fn(),

frontend/lib/hooks/__tests__/useTerminalModalState.test.tsx

@@ -1,6 +1,17 @@
 import { renderHook, act } from '@testing-library/react';
 import { useTerminalModalState } from '../useTerminalModalState';
 
+// Suppress console.warn during tests (fallback mode warnings are expected)
+const originalConsoleWarn = console.warn;
+
+beforeAll(() => {
+  console.warn = jest.fn();
+});
+
+afterAll(() => {
+  console.warn = originalConsoleWarn;
+});
+
 // Mock MUI hooks
 jest.mock('@mui/material', () => ({
   ...jest.requireActual('@mui/material'),