feat: add OI ranking data support and fix trader config update issues

- Add OI ranking data fetching and formatting for AI prompts
- Fix trader update not saving strategy_id, ai_model_id, initial_balance
- Fix AI API key not set for non-qwen/deepseek providers
- Add strategy_id to trader config API response
- Remove old trader from memory before reloading on update
- Clean up unused useTraderActions.ts

trader/auto_trader.go

@@ -773,6 +773,16 @@ func (at *AutoTrader) buildTradingContext() (*decision.Context, error) {
 		logger.Infof("📊 [%s] Successfully fetched quantitative data for %d symbols", at.name, len(ctx.QuantDataMap))
 	}
 
+	// 9. Get OI ranking data (market-wide position changes)
+	if strategyConfig.Indicators.EnableOIRanking {
+		logger.Infof("📊 [%s] Fetching OI ranking data...", at.name)
+		ctx.OIRankingData = at.strategyEngine.FetchOIRankingData()
+		if ctx.OIRankingData != nil {
+			logger.Infof("📊 [%s] OI ranking data ready: %d top, %d low positions",
+				at.name, len(ctx.OIRankingData.TopPositions), len(ctx.OIRankingData.LowPositions))
+		}
+	}
+
 	return ctx, nil
 }