[MoruTeaven]

概述

列内滚动时，把项目分组头钉在列的顶部。

看板每一列的列头（待办 / 进行中 / 待验收 + 数量）位于滚动容器之外，本身不会滚走；但列内的项目分组头（📁 项目名）会跟着卡片一起滚上去。列一长，正在看的项目名就先离开屏幕，剩下的卡片看不出属于哪个项目。

本次改动让分组头在列内滚动时吸顶；下一组到达顶部时把它顶走（sticky 的标准表现），因此不会出现「头显示 A 组、下面是 B 组卡片」的误导。

实测数据

用 Edge 驱动真实 DOM 测量第一列各分组头相对滚动容器顶部的偏移（单位 px，@2 = 贴在容器顶部，负值 = 已滚出）：

改动

src/client/styles.ts（.dsh-atb-ws-group-head，14 行）：

• position: sticky; top: 0; z-index: 2
• 底色改为不透明：三层叠加（--dsw-alias-bg-base 打底 + 列的 inset + hover 染色）精确复现该行背后的实际颜色，卡片从下方滑过时不会透出文字。原来的 rgba(128,128,128,.08) 半透明色在吸顶后会透字。

tests/sticky-group-head.spec.ts（新增）：断言两件容易静默回归的事——

1. 结构前提：sticky 元素的祖先链必须真的包含滚动容器 .dsh-atb-cards。若分组头被移到容器外，或中间插入带 overflow: hidden / transform 的祖先，sticky 会静默失效退化成普通行，而仅断言样式文本的测试抓不到这一点。
2. 样式规则本身：position: sticky / top: 0 存在，且底色带不透明基色。

lib/client.js：仓库约定提交预构建产物（GitHub 源安装免构建），已 npm run build 重建。

验证

• npx tsc --noEmit 通过
• npx vitest run 全量 408 个测试通过（30 个文件）
• 新增测试做过反向验证：临时把 position: sticky 改回 static，测试如期失败；恢复后通过
• 明暗两套主题下截图确认视觉正常

备注

未改动 changelog：当前 0.8.8 为已发布版本，按仓库惯例发版文案由维护者统一整理。若需要我在某个 dev 条目下补一条，告诉我即可。

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Summary (English)

Pins the project group header (📁 <project>) to the top of each column's card scroller.

The column head itself (待办 / 进行中 / 待验收 + count) never scrolls — it sits outside the scroller. What did scroll away was the project row, so on a long column the project label left the screen first and the remaining cards lost their grouping context.

The header now sticks; the next group pushes it out (standard sticky behaviour), so it never mislabels the cards beneath it.

Change — src/client/styles.ts: position: sticky; top: 0; z-index: 2 plus an opaque fill. Three stacked layers (board base + column inset + hover tint) reproduce exactly what sits behind the row, so cards sliding underneath never bleed through; the previous semi-transparent rgba(128,128,128,.08) would show text through once pinned.

Test — tests/sticky-group-head.spec.ts asserts (1) the sticky element's ancestor chain actually contains the scroll container (a header moved outside it, or an overflow: hidden / transform ancestor in between, silently degrades sticky to a normal row — a stylesheet-text-only assertion would miss it) and (2) the rule carries sticky + an opaque base. Verified the test fails when sticky is reverted to static.

Verified — tsc --noEmit clean; full suite 408 passed / 30 files; measured before/after offsets in a real browser (table above); screenshots checked in both themes. No changelog edit (0.8.8 is already released; the repo's convention is for the maintainer to write release notes).