feat:Replace emoji-based UI elements with lucide-react icons

What does this MR do and why?
This MR replaces emoji-based UI elements across the website with consistent lucide-react icons. The change improves visual consistency, makes the interface look more polished, and ensures icons render more uniformly across browsers and operating systems. It also updates related tests and fixes lint/build issues so the branch is ready to merge cleanly.

🚀 Key Features
Replaced emoji-based UI elements with lucide-react icons
Updated navbar icons and theme toggle icon handling
Updated event cards, project cards, summary cards, and dashboard sections
Replaced emoji usage in Contact, Projects, Events, AI Hackdays, Summer of AI, and About pages
Updated shared components to support React.ReactNode icon props where needed
Updated affected tests to match the new icon-based UI
Fixed lint warnings and verified build/test pipeline status

❓ Why this change?
Improves UI consistency across the website
Provides better control over styling, sizing, and alignment
Avoids platform-specific emoji rendering differences
Makes the design look more professional and maintainable
Keeps the codebase aligned with a reusable icon-based approach

✅ Checklist
✔ Modular and clean code
✔ Emoji-based UI replaced with icons
✔ Shared components updated for icon components
✔ UI working properly
✔ Tests updated and passing
✔ Lint passing
✔ Build successful
✔ Responsive behavior preserved

Related Issue
Replace emoji-based UI elements with consistent icons

#70 (closed)

ScreenShots
Before

After