[Frontend] — ENHANCEMENT: My Predictions page needs real data and filtering UI

[Olowodarey]

app/(authenticated)/my-predictions/page.tsx (linked from dashboard "View All") needs to be fully built out with real prediction data.

Required Features

• Tab filters: Active / Completed / Pending Resolution
• Sort by: Date, Stake Amount, Potential Payout
• Each card: market title, outcome chosen, stake, current probability, time remaining
• "Claim Payout" button on winning completed predictions
• Empty state when user has no predictions
• Pagination

Files to change:

• frontend/src/app/(authenticated)/my-predictions/page.tsx