fix: preserve explicit zero values in native relay requests

relay/channel/vertex/adaptor.go

@@ -21,6 +21,7 @@ import (
 	"github.com/QuantumNous/new-api/types"
 
 	"github.com/gin-gonic/gin"
+	"github.com/samber/lo"
 )
 
 const (
@@ -292,11 +293,11 @@ func (a *Adaptor) ConvertOpenAIRequest(c *gin.Context, info *relaycommon.RelayIn
 		imgReq := dto.ImageRequest{
 			Model:  request.Model,
 			Prompt: prompt,
-			N:      1,
+			N:      lo.ToPtr(uint(1)),
 			Size:   "1024x1024",
 		}
-		if request.N > 0 {
-			imgReq.N = uint(request.N)
+		if request.N != nil && *request.N > 0 {
+			imgReq.N = lo.ToPtr(uint(*request.N))
 		}
 		if request.Size != "" {
 			imgReq.Size = request.Size
@@ -305,7 +306,7 @@ func (a *Adaptor) ConvertOpenAIRequest(c *gin.Context, info *relaycommon.RelayIn
 			var extra map[string]any
 			if err := json.Unmarshal(request.ExtraBody, &extra); err == nil {
 				if n, ok := extra["n"].(float64); ok && n > 0 {
-					imgReq.N = uint(n)
+					imgReq.N = lo.ToPtr(uint(n))
 				}
 				if size, ok := extra["size"].(string); ok {
 					imgReq.Size = size

relay/channel/vertex/dto.go

@@ -10,12 +10,12 @@ type VertexAIClaudeRequest struct {
 	AnthropicVersion string              `json:"anthropic_version"`
 	Messages         []dto.ClaudeMessage `json:"messages"`
 	System           any                 `json:"system,omitempty"`
-	MaxTokens        uint                `json:"max_tokens,omitempty"`
+	MaxTokens        *uint               `json:"max_tokens,omitempty"`
 	StopSequences    []string            `json:"stop_sequences,omitempty"`
-	Stream           bool                `json:"stream,omitempty"`
+	Stream           *bool               `json:"stream,omitempty"`
 	Temperature      *float64            `json:"temperature,omitempty"`
-	TopP             float64             `json:"top_p,omitempty"`
-	TopK             int                 `json:"top_k,omitempty"`
+	TopP             *float64            `json:"top_p,omitempty"`
+	TopK             *int                `json:"top_k,omitempty"`
 	Tools            any                 `json:"tools,omitempty"`
 	ToolChoice       any                 `json:"tool_choice,omitempty"`
 	Thinking         *dto.Thinking       `json:"thinking,omitempty"`