refactor(SessionList): 注释掉旧的上下文菜单打开选项

- 注释掉了“Open as Editor”、“Open to the Side”和“Open in new Window”三项菜单
- 保留并新增了基于 JSONL 处理的上下文菜单选项
- 简化了上下文菜单内容，方便后续功能扩展
- 优化了菜单组件的可维护性和可读性

Author: hqwlkj

packages/vscode-ide-companion/src/webview/components/SessionList.tsx

@@ -399,7 +399,7 @@ export default function SessionList({
                                   <ItemActions className="shrink-0 text-xs text-muted-foreground"></ItemActions>
                                 </Item>
                               </ContextMenuTrigger>
-                              <ContextMenuContent className="w-64" side="right">
+                              <ContextMenuContent className="w-52" side="right">
                                 {/*<ContextMenuGroup>*/}
                                 {/*  <ContextMenuItem onClick={() => handleContextMenuOpen(s.id, "open")}>*/}
                                 {/*    <FileText className="h-4 w-4" />*/}