feat: upgrade to multi-model ensemble system

- Updated DB schemas: added 'strategy' to trades, new 'hourly_model_predictions' wide table
- Refactored backend: api/models.py, api/prediction_service.py to support wide format
- Updated trader: auto_trade_polymarket.py now logs strategy and saves to new table
- Updated frontend: index.html and app.js to display multi-model accuracy and trade strategy

data/trading_db.py

@@ -72,8 +72,8 @@ class TradingDatabase:
                     INSERT INTO trades (
                         timestamp, market_title, market_slug, model_name,
                         prediction, probability, action, price, amount, size,
-                        status, error_message, raw_data
-                    ) VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
+                        status, strategy, error_message, raw_data
+                    ) VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
                 '''
                 
                 cursor.execute(sql, (
@@ -88,6 +88,7 @@ class TradingDatabase:
                     trade_data.get('amount'),
                     trade_data.get('size'),
                     trade_data.get('status'),
+                    trade_data.get('strategy'),
                     trade_data.get('error_message'),
                     raw_data_json
                 ))