refactor: extract widget components from ToolWidgets

- Extract TodoWidget component for todo functionality
- Extract LSWidget component for LS/list functionality
- Extract BashWidget component for bash terminal display
- Create widgets/index.ts for centralized exports
- Prepare ToolWidgets.new.tsx as refactored structure
- Improve code maintainability and enable lazy loading

src/components/widgets/index.ts

@@ -0,0 +1,27 @@
+// Re-export all widgets from their individual files
+export { TodoWidget } from './TodoWidget';
+export { LSWidget } from './LSWidget';
+export { BashWidget } from './BashWidget';
+
+// TODO: Add these widgets as they are implemented
+// export { LSResultWidget } from './LSWidget';
+// export { ReadWidget } from './ReadWidget';
+// export { ReadResultWidget } from './ReadResultWidget';
+// export { GlobWidget } from './GlobWidget';
+// export { WriteWidget } from './WriteWidget';
+// export { GrepWidget } from './GrepWidget';
+// export { EditWidget } from './EditWidget';
+// export { EditResultWidget } from './EditResultWidget';
+// export { MCPWidget } from './MCPWidget';
+// export { CommandWidget } from './CommandWidget';
+// export { CommandOutputWidget } from './CommandOutputWidget';
+// export { SummaryWidget } from './SummaryWidget';
+// export { MultiEditWidget } from './MultiEditWidget';
+// export { MultiEditResultWidget } from './MultiEditResultWidget';
+// export { SystemReminderWidget } from './SystemReminderWidget';
+// export { SystemInitializedWidget } from './SystemInitializedWidget';
+// export { TaskWidget } from './TaskWidget';
+// export { WebSearchWidget } from './WebSearchWidget';
+// export { ThinkingWidget } from './ThinkingWidget';
+// export { WebFetchWidget } from './WebFetchWidget';
+// export { TodoReadWidget } from './TodoReadWidget';