fix(antigravity): place tool_result images in functionResponse.parts and unify mimeType

Move base64 image data from Claude tool_result into functionResponse.parts
as inlineData instead of outer sibling parts, preventing context bloat.
Unify all inlineData field naming to camelCase mimeType across Claude,
OpenAI, and Gemini translators. Add comprehensive edge case tests and
Gemini-side regression test for functionResponse.parts preservation.

Author: sususu98

internal/translator/antigravity/claude/antigravity_claude_request.go

@@ -223,14 +223,65 @@ func ConvertClaudeRequestToAntigravity(modelName string, inputRawJSON []byte, _
 								functionResponseJSON, _ = sjson.Set(functionResponseJSON, "response.result", responseData)
 							} else if functionResponseResult.IsArray() {
 								frResults := functionResponseResult.Array()
-								if len(frResults) == 1 {
-									functionResponseJSON, _ = sjson.SetRaw(functionResponseJSON, "response.result", frResults[0].Raw)
+								nonImageCount := 0
+								lastNonImageRaw := ""
+								filteredJSON := "[]"
+								imagePartsJSON := "[]"
+								for _, fr := range frResults {
+									if fr.Get("type").String() == "image" && fr.Get("source.type").String() == "base64" {
+										inlineDataJSON := `{}`
+										if mimeType := fr.Get("source.media_type").String(); mimeType != "" {
+											inlineDataJSON, _ = sjson.Set(inlineDataJSON, "mimeType", mimeType)
+										}
+										if data := fr.Get("source.data").String(); data != "" {
+											inlineDataJSON, _ = sjson.Set(inlineDataJSON, "data", data)
+										}
+
+										imagePartJSON := `{}`
+										imagePartJSON, _ = sjson.SetRaw(imagePartJSON, "inlineData", inlineDataJSON)
+										imagePartsJSON, _ = sjson.SetRaw(imagePartsJSON, "-1", imagePartJSON)
+										continue
+									}
+
+									nonImageCount++
+									lastNonImageRaw = fr.Raw
+									filteredJSON, _ = sjson.SetRaw(filteredJSON, "-1", fr.Raw)
+								}
+
+								if nonImageCount == 1 {
+									functionResponseJSON, _ = sjson.SetRaw(functionResponseJSON, "response.result", lastNonImageRaw)
+								} else if nonImageCount > 1 {
+									functionResponseJSON, _ = sjson.SetRaw(functionResponseJSON, "response.result", filteredJSON)
 								} else {
-									functionResponseJSON, _ = sjson.SetRaw(functionResponseJSON, "response.result", functionResponseResult.Raw)
+									functionResponseJSON, _ = sjson.Set(functionResponseJSON, "response.result", "")
+								}
+
+								// Place image data inside functionResponse.parts as inlineData
+								// instead of as sibling parts in the outer content, to avoid
+								// base64 data bloating the text context.
+								if gjson.Get(imagePartsJSON, "#").Int() > 0 {
+									functionResponseJSON, _ = sjson.SetRaw(functionResponseJSON, "parts", imagePartsJSON)
 								}
 
 							} else if functionResponseResult.IsObject() {
-								functionResponseJSON, _ = sjson.SetRaw(functionResponseJSON, "response.result", functionResponseResult.Raw)
+								if functionResponseResult.Get("type").String() == "image" && functionResponseResult.Get("source.type").String() == "base64" {
+									inlineDataJSON := `{}`
+									if mimeType := functionResponseResult.Get("source.media_type").String(); mimeType != "" {
+										inlineDataJSON, _ = sjson.Set(inlineDataJSON, "mimeType", mimeType)
+									}
+									if data := functionResponseResult.Get("source.data").String(); data != "" {
+										inlineDataJSON, _ = sjson.Set(inlineDataJSON, "data", data)
+									}
+
+									imagePartJSON := `{}`
+									imagePartJSON, _ = sjson.SetRaw(imagePartJSON, "inlineData", inlineDataJSON)
+									imagePartsJSON := "[]"
+									imagePartsJSON, _ = sjson.SetRaw(imagePartsJSON, "-1", imagePartJSON)
+									functionResponseJSON, _ = sjson.SetRaw(functionResponseJSON, "parts", imagePartsJSON)
+									functionResponseJSON, _ = sjson.Set(functionResponseJSON, "response.result", "")
+								} else {
+									functionResponseJSON, _ = sjson.SetRaw(functionResponseJSON, "response.result", functionResponseResult.Raw)
+								}
 							} else if functionResponseResult.Raw != "" {
 								functionResponseJSON, _ = sjson.SetRaw(functionResponseJSON, "response.result", functionResponseResult.Raw)
 							} else {
@@ -248,7 +299,7 @@ func ConvertClaudeRequestToAntigravity(modelName string, inputRawJSON []byte, _
 						if sourceResult.Get("type").String() == "base64" {
 							inlineDataJSON := `{}`
 							if mimeType := sourceResult.Get("media_type").String(); mimeType != "" {
-								inlineDataJSON, _ = sjson.Set(inlineDataJSON, "mime_type", mimeType)
+								inlineDataJSON, _ = sjson.Set(inlineDataJSON, "mimeType", mimeType)
 							}
 							if data := sourceResult.Get("data").String(); data != "" {
 								inlineDataJSON, _ = sjson.Set(inlineDataJSON, "data", data)