[TypeScript] Convert App.jsx to App.tsx

[12mv2]

Description

Help us migrate our codebase to TypeScript by converting src/webview/App.jsx to TypeScript (.tsx). This component is our main webview component that manages the overall layout and state of the visualization interface.

Task Requirements

1. Convert App.jsx to App.tsx
2. Ensure all component props and state are properly typed
3. Maintain existing functionality
4. Keep the same component structure

Steps

1. Create a copy of App.jsx as App.tsx
2. Add necessary React and TypeScript type imports
3. Define interfaces for props and state
4. Convert any JavaScript syntax to TypeScript
5. Test the component functionality
6. Remove the original .jsx file once confirmed working

Resources

• React TypeScript Cheatsheet
• Converting JSX to TSX Guide
• VS Code React TypeScript tutorial

Definition of Done

• File successfully converted to TypeScript
• All existing functionality works as before
• Component renders without type errors
• Extension builds successfully with npm run build