fix(build): resolve TypeScript errors and add missing dependencies

- Add missing zustand dependency to package.json
- Fix unused variable errors in ToolWidgets.tsx
- Remove invalid 'white' theme comparison in claudeSyntaxTheme.ts
- Add proper TypeScript types to stores using StateCreator pattern
- Add null checks and type casting in Settings.tsx filter operations
- Add onChange handler to Switch component to suppress React warning
- Add 'check' script for TypeScript validation

These changes ensure the TypeScript build passes without errors.

src/components/ToolWidgets.tsx

@@ -632,9 +632,6 @@ export const BashWidget: React.FC<{
   description?: string;
   result?: any;
 }> = ({ command, description, result }) => {
-  const { theme } = useTheme();
-  const syntaxTheme = getClaudeSyntaxTheme(theme);
-  
   // Extract result content if available
   let resultContent = '';
   let isError = false;