Enhance dashboard with advanced search, pagination and improved UX (#168)

Real-time search by contest/project name
Animated red circular clear button (X icon)
Status filters: All, Current, Upcoming, Past
Auto-reset to page 1 on changes
10 items per page with Previous/Next navigation
Page number buttons with active highlighting
Smart visibility (hides if only 1 page)
Shows count info ("Showing 1-10 of 25 contests")
<img width="1897" height="868" alt="image"
src="https://github.com/user-attachments/assets/7eb70535-2171-4756-846a-47297f408158"
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<img width="1898" height="876" alt="image"
src="https://github.com/user-attachments/assets/60b67c5a-02a4-4e2a-8eee-c38671495e05"
/>
<img width="1895" height="859" alt="image"
src="https://github.com/user-attachments/assets/2053d7bd-c195-41cf-923e-7abde606e55d"
/>

Author: GauriGupta21