Replace Mock Win Rate with Real Data

[wfnuser]

Description

Replace the mock win rate data in the frontend with actual calculated win rate from trading history.

Current Problem

• Win rate shows mock/dummy data instead of real trading performance
• Users cannot see their actual trading success rate
• Misleading performance metrics in the dashboard

Requirements

• Calculate real win rate from trades table in database
• Backend API endpoint to return actual win rate percentage
• Update frontend to fetch and display real win rate instead of mock data
• Show additional metrics like total trades count, wins/losses

Implementation

1. Query trades table to count profitable vs losing trades
2. Calculate win rate percentage (wins / total trades * 100)
3. Update the stats card to show real data
4. Remove mock data from frontend

Priority

High - Users need to see real performance metrics