Revert "feat: gemini-2.5-flash-image-preview 文本和图片输出计费"

This reverts commit a45513a7a6.

service/token_counter.go

@@ -336,7 +336,7 @@ func CountRequestToken(c *gin.Context, meta *types.TokenCountMeta, info *relayco
 	for i, file := range meta.Files {
 		switch file.FileType {
 		case types.FileTypeImage:
-			if info.RelayFormat == types.RelayFormatGemini && !strings.HasPrefix(model, "gemini-2.5-flash-image-preview") {
+			if info.RelayFormat == types.RelayFormatGemini {
 				tkm += 256
 			} else {
 				token, err := getImageToken(file, model, info.IsStream)