fix: prevent DeepSeek token overflow with product-level limits (#1431)

* feat: enforce strategy limits to prevent token overflow

* fix: tune token limits after real-world testing

- Relax kline max 20→30, timeframes 3→4 (tested ~41K tokens, safe under 131K)
- Restore ranking limits to original [5,10,15,20] options (only ~1.5K token impact)
- Add static coins limit (max 3) with toast notification
- Add timeframe limit toast when exceeding 4
- Log SSE token usage (prompt/completion/total) from API response
- Fix nil logger crash in claw402 data client (engine.go)

* feat: add token estimation functionality for strategy configurations

* feat: add discard changes button in Strategy Studio for unsaved modifications

* feat: retain selected strategy after saving in Strategy Studio

* feat: enhance strategy display in Strategy Studio with improved layout and sorting of token limits

* refactor: improve layout and styling of stats display in CompetitionPage

* refactor: replace select elements with NofxSelect component for improved consistency in strategy configuration forms

* style: update NofxSelect component to use smaller text size for improved readability

* feat: implement token overflow handling in strategy updates and UI

---------

Co-authored-by: Dean <afei.wuhao@gmail.com>

api/server.go

@@ -110,6 +110,7 @@ func (s *Server) setupRoutes() {
 
 		// Public strategy market (no authentication required)
 		s.route(api, "GET", "/strategies/public", "Public strategy market", s.handlePublicStrategies)
+		s.route(api, "POST", "/strategies/estimate-tokens", "Estimate token usage for a strategy config", s.handleEstimateTokens)
 
 		// Authentication related routes (no authentication required)
 		s.route(api, "POST", "/register", "Register new user", s.handleRegister)

api/strategy.go

@@ -31,6 +31,20 @@ func validateStrategyConfig(config *store.StrategyConfig) []string {
 	return warnings
 }
 
+// handleEstimateTokens estimates token usage for a strategy config (no auth required, pure computation)
+func (s *Server) handleEstimateTokens(c *gin.Context) {
+	var req struct {
+		Config store.StrategyConfig `json:"config" binding:"required"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil {
+		SafeBadRequest(c, "Invalid request parameters")
+		return
+	}
+
+	estimate := req.Config.EstimateTokens()
+	c.JSON(http.StatusOK, estimate)
+}
+
 // handlePublicStrategies Get public strategies for strategy market (no auth required)
 func (s *Server) handlePublicStrategies(c *gin.Context) {
 	strategies, err := s.store.Strategy().ListPublic()
@@ -289,6 +303,25 @@ func (s *Server) handleUpdateStrategy(c *gin.Context) {
 		return
 	}
 
+	// Token overflow check — block save if all models exceed context limits
+	if mergedConfig.StrategyType == "" || mergedConfig.StrategyType == "ai_trading" {
+		estimate := mergedConfig.EstimateTokens()
+		allExceed := true
+		for _, ml := range estimate.ModelLimits {
+			if ml.UsagePct <= 100 {
+				allExceed = false
+				break
+			}
+		}
+		if allExceed && len(estimate.ModelLimits) > 0 {
+			c.JSON(http.StatusBadRequest, gin.H{
+				"error":          fmt.Sprintf("Estimated %d tokens exceeds all known model context limits. Reduce coins, timeframes, or K-line count.", estimate.Total),
+				"token_estimate": estimate,
+			})
+			return
+		}
+	}
+
 	// Validate merged configuration and collect warnings
 	warnings := validateStrategyConfig(&mergedConfig)