优化图片格式处理，统一将'jpg'格式转换为'jpeg'，新增标准化和MIME类型转换功能，以确保API兼容性和提高代码可读性(最主要的还是为了gemini)

src/llm_models/model_client/aiohttp_gemini_client.py

@@ -20,6 +20,29 @@ from ..payload_content.tool_option import ToolOption, ToolParam, ToolCall
 logger = get_logger("AioHTTP-Gemini客户端")
 
 
+def _format_to_mime_type(image_format: str) -> str:
+    """
+    将图片格式转换为正确的MIME类型
+    
+    Args:
+        image_format (str): 图片格式 (如 'jpg', 'png' 等)
+        
+    Returns:
+        str: 对应的MIME类型
+    """
+    format_mapping = {
+        "jpg": "image/jpeg",
+        "jpeg": "image/jpeg", 
+        "png": "image/png",
+        "webp": "image/webp",
+        "gif": "image/gif",
+        "heic": "image/heic",
+        "heif": "image/heif"
+    }
+    
+    return format_mapping.get(image_format.lower(), f"image/{image_format.lower()}")
+
+
 def _convert_messages(messages: list[Message]) -> tuple[list[dict], list[str] | None]:
     """
     转换消息格式 - 将消息转换为Gemini REST API所需的格式
@@ -46,7 +69,7 @@ def _convert_messages(messages: list[Message]) -> tuple[list[dict], list[str] |
                 if isinstance(item, tuple):  # (format, base64_data)
                     parts.append({
                         "inline_data": {
-                            "mime_type": f"image/{item[0].lower()}",
+                            "mime_type": _format_to_mime_type(item[0]),
                             "data": item[1]
                         }
                     })

src/llm_models/model_client/gemini_client.py

@@ -61,6 +61,25 @@ def _convert_messages(
     :param messages: 消息列表
     :return: 转换后的消息列表(和可能存在的system消息)
     """
+    
+    def _get_correct_mime_type(image_format: str) -> str:
+        """
+        获取正确的MIME类型，修复jpg到jpeg的映射问题
+        :param image_format: 图片格式
+        :return: 正确的MIME类型
+        """
+        # 标准化格式名称，解决jpg/jpeg兼容性问题
+        format_mapping = {
+            "jpg": "jpeg",
+            "jpeg": "jpeg", 
+            "png": "png",
+            "webp": "webp",
+            "heic": "heic",
+            "heif": "heif",
+            "gif": "gif"
+        }
+        normalized_format = format_mapping.get(image_format.lower(), image_format.lower())
+        return f"image/{normalized_format}"
 
     def _convert_message_item(message: Message) -> Content:
         """
@@ -84,7 +103,7 @@ def _convert_messages(
                 if isinstance(item, tuple):
                     image_format = "jpeg" if item[0].lower() == "jpg" else item[0].lower()
                     content.append(
-                        Part.from_bytes(data=base64.b64decode(item[1]), mime_type=f"image/{image_format}")
+                        Part.from_bytes(data=base64.b64decode(item[1]), mime_type=_get_correct_mime_type(item[0]))
                     )
                 elif isinstance(item, str):
                     content.append(Part.from_text(text=item))