Fix TypeScript errors in designer-modes example

[Copilot]

The designer-modes example was failing CI type checks with TS6133 (unused React import) and TS2307 (CSS module not found).

Changes

• App.tsx: Remove unnecessary React namespace import (automatic JSX runtime doesn't require it)
• main.tsx: Use named imports (StrictMode, createRoot) instead of namespace imports
• tsconfig.json: Add "types": ["vite/client"] for CSS import type definitions

-import React, { useState } from 'react';
+import { useState } from 'react';

-import React from 'react';
-import ReactDOM from 'react-dom/client';
+import { StrictMode } from 'react';
+import { createRoot } from 'react-dom/client';

The tsconfig already specified "jsx": "react-jsx" which enables automatic JSX transformation, making the React namespace import redundant. Vite client types are required for module declarations like CSS imports.

Original prompt

引用: https://github.com/objectstack-ai/objectui/actions/runs/21026040003/job/60450980468#step:6:1

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[Copilot]

Pull request overview

This PR fixes TypeScript compilation errors in the designer-modes example that were causing CI failures. The changes modernize the React imports to align with the automatic JSX runtime configuration and add missing type definitions for Vite's module resolution.

Changes:

• Removed redundant React namespace imports in favor of named imports
• Added Vite client types to tsconfig for CSS module declarations

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
examples/designer-modes/tsconfig.json	Added "types": ["vite/client"] to resolve CSS import type errors
examples/designer-modes/src/main.tsx	Changed to named imports (StrictMode, createRoot) instead of namespace imports
examples/designer-modes/src/App.tsx	Removed unused React namespace import, keeping only useState

[huangyiirene]

@copilot fix check

[huangyiirene]

@copilot fix type check

[github-actions]

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• ✅ Type check passed
• ✅ Tests passed
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