refactor: migrating Checkbox component to typescript

[SAHU-01]

Refactored code for #2388 - Checkbox component TypeScript migration

Changes

• Added src/components/checkbox/checkbox.tsx (functional TSX component with CheckboxProps interface)
• Deleted legacy src/components/checkbox/Checkbox.js
• Converted Storybook to TSX: checkbox.stories.tsx with proper Meta/StoryObj typing
• Removed PropTypes and defaultProps in favor of TypeScript interfaces and default parameters
• Updated onChange handler to use optional chaining for type safety
• Fixed case-sensitive import issues - updated src/files/files-grid/grid-file.tsx to use lowercase path
• Follows kebab-case naming convention
• Exports CheckboxProps interface for external usage

Tests

• TypeScript compilation: No errors (npx tsc --noEmit)
• Lint: No issues (npm run lint)
• Storybook stories: All stories render correctly
• App functionality: Working correctly

Screenshot/Recording

Screen.Recording.2025-09-29.at.1.12.36.AM.mp4

Screen.Recording.2025-09-29.at.1.15.47.AM.mp4

Reviewer: @SgtPooki