feat: Improve embedding request handling and support across channels

- Update EmbeddingRequest DTO to support more flexible input types
- Add input parsing method to handle various input formats
- Implement ConvertEmbeddingRequest for multiple channel adaptors
- Remove relayMode parameter from EmbeddingHelper
- Add input validation for embedding requests
- Simplify embedding request conversion for different channels

relay/channel/ali/adaptor.go

@@ -49,9 +49,6 @@ func (a *Adaptor) ConvertRequest(c *gin.Context, info *relaycommon.RelayInfo, re
 		return nil, errors.New("request is nil")
 	}
 	switch info.RelayMode {
-	case constant.RelayModeEmbeddings:
-		baiduEmbeddingRequest := embeddingRequestOpenAI2Ali(*request)
-		return baiduEmbeddingRequest, nil
 	default:
 		aliReq := requestOpenAI2Ali(*request)
 		return aliReq, nil
@@ -68,8 +65,7 @@ func (a *Adaptor) ConvertRerankRequest(c *gin.Context, relayMode int, request dt
 }
 
 func (a *Adaptor) ConvertEmbeddingRequest(c *gin.Context, info *relaycommon.RelayInfo, request dto.EmbeddingRequest) (any, error) {
-	//TODO implement me
-	return nil, errors.New("not implemented")
+	return embeddingRequestOpenAI2Ali(request), nil
 }
 
 func (a *Adaptor) ConvertAudioRequest(c *gin.Context, info *relaycommon.RelayInfo, request dto.AudioRequest) (io.Reader, error) {

relay/channel/ali/text.go

@@ -25,9 +25,12 @@ func requestOpenAI2Ali(request dto.GeneralOpenAIRequest) *dto.GeneralOpenAIReque
 	return &request
 }
 
-func embeddingRequestOpenAI2Ali(request dto.GeneralOpenAIRequest) *AliEmbeddingRequest {
+func embeddingRequestOpenAI2Ali(request dto.EmbeddingRequest) *AliEmbeddingRequest {
+	if request.Model == "" {
+		request.Model = "text-embedding-v1"
+	}
 	return &AliEmbeddingRequest{
-		Model: "text-embedding-v1",
+		Model: request.Model,
 		Input: struct {
 			Texts []string `json:"texts"`
 		}{