revert(mcp): 移除MCP SSE客户端及工具集成支持

src/plugin_system/apis/tool_api.py

@@ -17,12 +17,7 @@ def get_tool_instance(tool_name: str) -> BaseTool | None:
         plugin_config = None
 
     tool_class: type[BaseTool] = component_registry.get_component_class(tool_name, ComponentType.TOOL)  # type: ignore
-    if tool_class:
-        return tool_class(plugin_config)
-
-    # 如果不是常规工具，检查是否是MCP工具
-    # MCP工具不需要返回实例，会在execute_tool_call中特殊处理
-    return None
+    return tool_class(plugin_config) if tool_class else None
 
 
 def get_llm_available_tool_definitions():
@@ -34,17 +29,4 @@ def get_llm_available_tool_definitions():
     from src.plugin_system.core import component_registry
 
     llm_available_tools = component_registry.get_llm_available_tools()
-    tool_definitions = [(name, tool_class.get_tool_definition()) for name, tool_class in llm_available_tools.items()]
 
-    # 添加MCP工具
-    try:
-        from src.plugin_system.utils.mcp_tool_provider import mcp_tool_provider
-
-        mcp_tools = mcp_tool_provider.get_mcp_tool_definitions()
-        tool_definitions.extend(mcp_tools)
-        if mcp_tools:
-            logger.debug(f"已添加 {len(mcp_tools)} 个MCP工具到可用工具列表")
-    except Exception as e:
-        logger.debug(f"获取MCP工具失败（可能未配置）: {e}")
-
-    return tool_definitions