Copy rewrapped should handle with nested quotes

I just encountered this case where I want to copy-paste hunks of the following out of a Claude Code session:

```
Biggest copy regression: Tiling Layout

This section lost its selling power. Previous version
sold the use case:

▎ "Run builds, agents, servers, and scripts side by
▎ side. Minimize the ones you're not watching to a
▎ compact status indicator — every pane keeps running
▎ and every alert still fires whether minimized or
▎ not."

Current version (lines 35–39) sells the mechanics:

▎ "You can spawn, layout, and relayout everything in
▎ the terminal using any of: default tmux shortcuts,
▎ intuitive modern shortcuts, the mouse"

Readers on a marketplace decide based on "can I
picture myself using this?" The old version paints
that picture; the new version reads like a feature
inventory. Also: the heading promises "Minimize /
Maximize" but the body never mentions either — the
feature claim is in the keyboard table only.
```

Here is what "Copy rewrapped" does right now:

```
Biggest copy regression: Tiling Layout

This section lost its selling power. Previous version sold the use case:

▎ "Run builds, agents, servers, and scripts side by ▎ side. Minimize the ones you're not watching to a ▎ compact status indicator — every pane keeps running ▎ and every alert still fires whether minimized or ▎ not."

Current version (lines 35–39) sells the mechanics:

▎ "You can spawn, layout, and relayout everything in ▎ the terminal using any of: default tmux shortcuts, ▎ intuitive modern shortcuts, the mouse"

Readers on a marketplace decide based on "can I picture myself using this?" The old version paints that picture; the new version reads like a feature inventory. Also: the heading promises "Minimize / Maximize" but the body never mentions either — the feature claim is in the keyboard table only.

Suggested direction: lead with the use case, then note that you can drive it with mouse/modern shortcuts/tmux shortcuts.
```

Should probably use the markdown `>` convention to deal with nesting like this.

Bắt đầu với lệnh hoặc action Copy rewrapped và tái hiện ví dụ về trích dẫn lồng nhau từ issue, kiểm tra cách các marker blockquote của Markdown được xử lý. Hoàn thành khi văn bản được sao chép giữ nguyên cấu trúc `>` lồng nhau thay vì làm phẳng các dòng được trích dẫn, đồng thời hành vi sao chép hiện có vẫn được giữ nguyên.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.