fix: preserve explicit zero values in native relay requests

relay/claude_handler.go

@@ -47,8 +47,9 @@ func ClaudeHelper(c *gin.Context, info *relaycommon.RelayInfo) (newAPIError *typ
 	}
 	adaptor.Init(info)
 
-	if request.MaxTokens == 0 {
-		request.MaxTokens = uint(model_setting.GetClaudeSettings().GetDefaultMaxTokens(request.Model))
+	if request.MaxTokens == nil || *request.MaxTokens == 0 {
+		defaultMaxTokens := uint(model_setting.GetClaudeSettings().GetDefaultMaxTokens(request.Model))
+		request.MaxTokens = &defaultMaxTokens
 	}
 
 	if baseModel, effortLevel, ok := reasoning.TrimEffortSuffix(request.Model); ok && effortLevel != "" &&
@@ -58,25 +59,25 @@ func ClaudeHelper(c *gin.Context, info *relaycommon.RelayInfo) (newAPIError *typ
 			Type: "adaptive",
 		}
 		request.OutputConfig = json.RawMessage(fmt.Sprintf(`{"effort":"%s"}`, effortLevel))
-		request.TopP = 0
+		request.TopP = common.GetPointer[float64](0)
 		request.Temperature = common.GetPointer[float64](1.0)
 		info.UpstreamModelName = request.Model
 	} else if model_setting.GetClaudeSettings().ThinkingAdapterEnabled &&
 		strings.HasSuffix(request.Model, "-thinking") {
 		if request.Thinking == nil {
 			// 因为BudgetTokens 必须大于1024
-			if request.MaxTokens < 1280 {
-				request.MaxTokens = 1280
+			if request.MaxTokens == nil || *request.MaxTokens < 1280 {
+				request.MaxTokens = common.GetPointer[uint](1280)
 			}
 
 			// BudgetTokens 为 max_tokens 的 80%
 			request.Thinking = &dto.Thinking{
 				Type:         "enabled",
-				BudgetTokens: common.GetPointer[int](int(float64(request.MaxTokens) * model_setting.GetClaudeSettings().ThinkingAdapterBudgetTokensPercentage)),
+				BudgetTokens: common.GetPointer[int](int(float64(*request.MaxTokens) * model_setting.GetClaudeSettings().ThinkingAdapterBudgetTokensPercentage)),
 			}
 			// TODO: 临时处理
 			// https://docs.anthropic.com/en/docs/build-with-claude/extended-thinking#important-considerations-when-using-extended-thinking
-			request.TopP = 0
+			request.TopP = common.GetPointer[float64](0)
 			request.Temperature = common.GetPointer[float64](1.0)
 		}
 		if !model_setting.ShouldPreserveThinkingSuffix(info.OriginModelName) {