[UI] 🎨 Add application icon

[ahmdkaml]

🎨 Problem

The frontend currently does not have a dedicated application icon.

A proper icon should be included as part of the React application's basic branding and browser experience.

🎯 Goal

Add an application icon and configure the frontend to use it.

✅ Acceptance Criteria

• An appropriate ZemoLibrary application icon is created
• The icon is added to the frontend assets
• index.html references the icon correctly
• The icon appears in the browser tab
• The icon is included in the production Vite build
• The icon works correctly when deployed to GitHub Pages under /zemoLibrary/

📌 Notes

The icon should be lightweight and suitable for use as both a favicon and application branding.