Allow end-aligned truncation for path and branch footer items

Describe the feature or problem you'd like to solve

When the path or branch name is too long, only the end is truncated.

Proposed solution

Add a per-item truncation setting to  /footer  (and  /statusline ) for values such as the current working directory and Git branch. Support at least  start  (current behavior),  end , and optionally  middle  truncation. With  end  selected, render an ellipsis followed by the trailing portion of the value—for example,  …\foo\.worktrees\bar  and  …/feature-name —so the most distinguishing directory and branch suffix remain visible in narrow terminals. Persist the preference with the existing footer configuration.

Example prompts or workflows

No response

Additional context

No response

先定位 footer 和 statusline 的配置与渲染入口，然后跟踪当前路径和分支值的截断与持久化方式。验证现有的从开头截断行为，并确定每个项目的开头、结尾或中间偏好应放在哪里。完成的标准是两个界面都能保留该设置，并在窄终端中显示请求的路径或分支末尾部分，同时使用省略号。