**feat(translator): improve content processing and Antigravity request conversion**

- Refactored response translation logic to support mixed content types (`input_text`, `output_text`, `input_image`) with better role assignments and part handling.
- Added image processing logic for embedding inline data with MIME type and base64 encoded content.
- Updated Antigravity request conversion to replace Gemini CLI references for consistency.

internal/translator/antigravity/openai/responses/antigravity_openai-responses_request.go

@@ -3,12 +3,12 @@ package responses
 import (
 	"bytes"
 
-	. "github.com/router-for-me/CLIProxyAPI/v6/internal/translator/gemini-cli/gemini"
+	. "github.com/router-for-me/CLIProxyAPI/v6/internal/translator/antigravity/gemini"
 	. "github.com/router-for-me/CLIProxyAPI/v6/internal/translator/gemini/openai/responses"
 )
 
 func ConvertOpenAIResponsesRequestToAntigravity(modelName string, inputRawJSON []byte, stream bool) []byte {
 	rawJSON := bytes.Clone(inputRawJSON)
 	rawJSON = ConvertOpenAIResponsesRequestToGemini(modelName, rawJSON, stream)
-	return ConvertGeminiRequestToGeminiCLI(modelName, rawJSON, stream)
+	return ConvertGeminiRequestToAntigravity(modelName, rawJSON, stream)
 }

internal/translator/gemini/openai/responses/gemini_openai-responses_request.go

@@ -67,39 +67,101 @@ func ConvertOpenAIResponsesRequestToGemini(modelName string, inputRawJSON []byte
 				// even when the message.role is "user". We split such items into distinct Gemini messages
 				// with roles derived from the content type to match docs/convert-2.md.
 				if contentArray := item.Get("content"); contentArray.Exists() && contentArray.IsArray() {
+					currentRole := ""
+					var currentParts []string
+
+					flush := func() {
+						if currentRole == "" || len(currentParts) == 0 {
+							currentParts = nil
+							return
+						}
+						one := `{"role":"","parts":[]}`
+						one, _ = sjson.Set(one, "role", currentRole)
+						for _, part := range currentParts {
+							one, _ = sjson.SetRaw(one, "parts.-1", part)
+						}
+						out, _ = sjson.SetRaw(out, "contents.-1", one)
+						currentParts = nil
+					}
+
 					contentArray.ForEach(func(_, contentItem gjson.Result) bool {
 						contentType := contentItem.Get("type").String()
 						if contentType == "" {
 							contentType = "input_text"
 						}
+
+						effRole := "user"
+						if itemRole != "" {
+							switch strings.ToLower(itemRole) {
+							case "assistant", "model":
+								effRole = "model"
+							default:
+								effRole = strings.ToLower(itemRole)
+							}
+						}
+						if contentType == "output_text" {
+							effRole = "model"
+						}
+						if effRole == "assistant" {
+							effRole = "model"
+						}
+
+						if currentRole != "" && effRole != currentRole {
+							flush()
+							currentRole = ""
+						}
+						if currentRole == "" {
+							currentRole = effRole
+						}
+
+						var partJSON string
 						switch contentType {
 						case "input_text", "output_text":
 							if text := contentItem.Get("text"); text.Exists() {
-								effRole := "user"
-								if itemRole != "" {
-									switch strings.ToLower(itemRole) {
-									case "assistant", "model":
-										effRole = "model"
-									default:
-										effRole = strings.ToLower(itemRole)
+								partJSON = `{"text":""}`
+								partJSON, _ = sjson.Set(partJSON, "text", text.String())
+							}
+						case "input_image":
+							imageURL := contentItem.Get("image_url").String()
+							if imageURL == "" {
+								imageURL = contentItem.Get("url").String()
+							}
+							if imageURL != "" {
+								mimeType := "application/octet-stream"
+								data := ""
+								if strings.HasPrefix(imageURL, "data:") {
+									trimmed := strings.TrimPrefix(imageURL, "data:")
+									mediaAndData := strings.SplitN(trimmed, ";base64,", 2)
+									if len(mediaAndData) == 2 {
+										if mediaAndData[0] != "" {
+											mimeType = mediaAndData[0]
+										}
+										data = mediaAndData[1]
+									} else {
+										mediaAndData = strings.SplitN(trimmed, ",", 2)
+										if len(mediaAndData) == 2 {
+											if mediaAndData[0] != "" {
+												mimeType = mediaAndData[0]
+											}
+											data = mediaAndData[1]
+										}
 									}
 								}
-								if contentType == "output_text" {
-									effRole = "model"
+								if data != "" {
+									partJSON = `{"inline_data":{"mime_type":"","data":""}}`
+									partJSON, _ = sjson.Set(partJSON, "inline_data.mime_type", mimeType)
+									partJSON, _ = sjson.Set(partJSON, "inline_data.data", data)
 								}
-								if effRole == "assistant" {
-									effRole = "model"
-								}
-								one := `{"role":"","parts":[]}`
-								one, _ = sjson.Set(one, "role", effRole)
-								textPart := `{"text":""}`
-								textPart, _ = sjson.Set(textPart, "text", text.String())
-								one, _ = sjson.SetRaw(one, "parts.-1", textPart)
-								out, _ = sjson.SetRaw(out, "contents.-1", one)
 							}
 						}
+
+						if partJSON != "" {
+							currentParts = append(currentParts, partJSON)
+						}
 						return true
 					})
+
+					flush()
 				}
 
 			case "function_call":