fix: enhance mcp_source logic in McpServersDialog

--bug=1060762 --user=刘瑞斌 【应用】v2.0.2版本已存在的应用的MCP，升级版本后，编辑界面，MCP回显错误 https://www.tapd.cn/62980211/s/1760254

Author: liuruibin

ui/src/views/application/component/McpServersDialog.vue

@@ -145,7 +145,15 @@ function mcpSourceChange() {
 
 const open = (data: any, selectOptions: any) => {
   form.value = {...form.value, ...data}
-  form.value.mcp_source = data.mcp_source || 'referencing'
+  if (data.mcp_servers) {
+    form.value.mcp_source = 'custom'
+  } else if (data.mcp_tool_id) {
+    form.value.mcp_source = 'referencing'
+    form.value.mcp_tool_id = data.mcp_tool_id
+    form.value.mcp_servers = ''
+  } else {
+    form.value.mcp_source = data.mcp_source || 'referencing'
+  }
   dialogVisible.value = true
   mcpToolSelectOptions.value = selectOptions || []
 }