feat: Add SystemPromptTemplate edit support (PR #339)

- Allow users to modify SystemPromptTemplate when editing Trader
- Enable dynamic strategy switching (default/aggressive/conservative)
- Support A/B testing of different trading strategies
- Maintain backward compatibility with existing data
- Complete full data flow from database through UI to persistence

api/server.go

@@ -453,17 +453,18 @@ func (s *Server) handleCreateTrader(c *gin.Context) {
 
 // UpdateTraderRequest 更新交易员请求
 type UpdateTraderRequest struct {
-	Name               string  `json:"name" binding:"required"`
-	AIModelID          string  `json:"ai_model_id" binding:"required"`
-	ExchangeID         string  `json:"exchange_id" binding:"required"`
-	InitialBalance     float64 `json:"initial_balance"`
-	BTCETHLeverage     int     `json:"btc_eth_leverage"`
-	AltcoinLeverage    int     `json:"altcoin_leverage"`
-	TradingSymbols     string  `json:"trading_symbols"`
-	CustomPrompt       string  `json:"custom_prompt"`
-	OverrideBasePrompt bool    `json:"override_base_prompt"`
-	IsCrossMargin      *bool   `json:"is_cross_margin"`
-	ScanIntervalMinutes int     `json:"scan_interval_minutes"`
+	Name                 string  `json:"name" binding:"required"`
+	AIModelID            string  `json:"ai_model_id" binding:"required"`
+	ExchangeID           string  `json:"exchange_id" binding:"required"`
+	InitialBalance       float64 `json:"initial_balance"`
+	ScanIntervalMinutes  int     `json:"scan_interval_minutes"`
+	BTCETHLeverage       int     `json:"btc_eth_leverage"`
+	AltcoinLeverage      int     `json:"altcoin_leverage"`
+	TradingSymbols       string  `json:"trading_symbols"`
+	CustomPrompt         string  `json:"custom_prompt"`
+	OverrideBasePrompt   bool    `json:"override_base_prompt"`
+	SystemPromptTemplate string  `json:"system_prompt_template"`
+	IsCrossMargin        *bool   `json:"is_cross_margin"`
 }
 
 // handleUpdateTrader 更新交易员配置
@@ -519,12 +520,18 @@ func (s *Server) handleUpdateTrader(c *gin.Context) {
 		scanIntervalMinutes = existingTrader.ScanIntervalMinutes // 保持原值
 	}
 
+	// 设置系统提示词模板，允许更新
+	systemPromptTemplate := req.SystemPromptTemplate
+	if systemPromptTemplate == "" {
+		systemPromptTemplate = existingTrader.SystemPromptTemplate // 保持原值
+	}
+
 	// 更新交易员配置
 	trader := &config.TraderRecord{
-		ID:                  traderID,
-		UserID:              userID,
-		Name:                req.Name,
-		AIModelID:           req.AIModelID,
+		ID:                   traderID,
+		UserID:               userID,
+		Name:                 req.Name,
+		AIModelID:            req.AIModelID,
 		ExchangeID:           req.ExchangeID,
 		InitialBalance:       req.InitialBalance,
 		BTCETHLeverage:       btcEthLeverage,
@@ -532,7 +539,7 @@ func (s *Server) handleUpdateTrader(c *gin.Context) {
 		TradingSymbols:       req.TradingSymbols,
 		CustomPrompt:         req.CustomPrompt,
 		OverrideBasePrompt:   req.OverrideBasePrompt,
-		SystemPromptTemplate: existingTrader.SystemPromptTemplate, // 保持原值
+		SystemPromptTemplate: systemPromptTemplate,
 		IsCrossMargin:        isCrossMargin,
 		ScanIntervalMinutes:  scanIntervalMinutes,
 		IsRunning:            existingTrader.IsRunning, // 保持原值