fix: preserve explicit zero values in native relay requests

relay/channel/ali/text.go

@@ -2,6 +2,7 @@ package ali
 
 import (
 	"github.com/QuantumNous/new-api/dto"
+	"github.com/samber/lo"
 )
 
 // https://help.aliyun.com/document_detail/613695.html?spm=a2c4g.2399480.0.0.1adb778fAdzP9w#341800c0f8w0r
@@ -9,10 +10,11 @@ import (
 const EnableSearchModelSuffix = "-internet"
 
 func requestOpenAI2Ali(request dto.GeneralOpenAIRequest) *dto.GeneralOpenAIRequest {
-	if request.TopP >= 1 {
-		request.TopP = 0.999
-	} else if request.TopP <= 0 {
-		request.TopP = 0.001
+	topP := lo.FromPtrOr(request.TopP, 0)
+	if topP >= 1 {
+		request.TopP = lo.ToPtr(0.999)
+	} else if topP <= 0 {
+		request.TopP = lo.ToPtr(0.001)
 	}
 	return &request
 }