✨ Bookmark Navigator

### Description

Introduce a Bookmark Navigator panel that allows users to view, organize, and quickly jump to bookmarked lines across files. This would streamline navigation in large codebases and improve productivity when working across multiple sections of a project.

### Proposed Features

- List all bookmarks in the current workspace/project
- Show file name, line number, and a preview of the bookmarked line
- Allow bookmarks to be renamed or annotated with custom labels
- Clicking a bookmark scrolls the editor to the corresponding line
- Ability to group or filter bookmarks by file, folder, or tag
- Keyboard shortcuts for toggling the navigator and adding/removing bookmarks
- Option to persist bookmarks across sessions

### Additional Context:

This would be especially useful for users who frequently jump between key parts of their code or need to track multiple areas while debugging or implementing features.

该 issue 未指定任何文件、测试或入口点；首先调查 CodeEdit macOS 应用中现有的书签和编辑器导航实现。在实现之前，为列表显示、跳转到、组织、标记、筛选、键盘控制和持久化定义验收检查项。

由索引模型根据 Issue 内容生成。