[Feat] [Studio]: Add interactive GitHub links to brand asset cards

[d3vpool]

Summary

• Made the Logo Path card clickable with a GitHub link
• Made the Design References card clickable with a GitHub link
• Added external link icons using lucide-react

Testing

• Verified links open correctly
• Tested locally on /style-guide
• Ran lint and formatting checks

Closes #60

[Gautam25Raj]

Hi @d3vpool, thanks for taking the initiative to submit this PR!

Before we can merge this, we have a few guidelines and feedback we'd like you to address:

1. Contribution Workflow: For future issues, please comment on the issue first to discuss it and get assigned before starting work. This helps our team coordinate and avoids duplicate efforts among contributors.

2. Use Next.js <Link>: Please use Next.js's <Link> component (imported from "next/link") instead of the standard HTML <a> tags. This ensures consistent navigation behavior and conforms to the project's codebase standards.

3. Missing Hover Interactions: The cards are wrapped in links but don't change visual state on hover. Adding transition effects and subtle hover backgrounds (e.g., hover:bg-muted/10 or changing text colors on hover) will make the cards feel truly interactive.

4. Code Formatting & Linting: It looks like some of the code is unformatted. Please run the following commands in the root of the project to clean it up before updating the PR:

   npm run format:write
   npm run lint
   

5. Accessibility (a11y) Gaps:

   • The ExternalLink icon needs aria-hidden="true" so screen readers don't try to announce it.

[d3vpool]

Thanks for the review and for applying the suggested fixes. Really appreciate the guidance!