[argszero]

Summary

Implements item D (搜索增强 / Search enhancement) of the UI/UE round-3 wave (rant 2026-08-17T18:06:09, branch feat/ui-ue-round3, version v1.18).

Three acceptance points, all covered across the four search boxes (#mk-search market / #ak-search API keys / #od-search departments / #ops-search operator users):

1. Debounce (~150ms) — new wireSearch(input, render) helper: typing no longer re-renders the whole table on every keystroke; consecutive inputs coalesce into a single render.
2. Keyword highlight — new hl(text, rawQ) helper: escape HTML first, then wrap case-insensitive matches in <mark> (regex-escaped user input, & < > aligned with the escaped text). Highlight is cleared automatically when the query is reset. mark styled with --accent-soft background + --accent-text color (WCAG-friendly in both dark and light themes).
3. Clear × button — each search input is wrapped in a .search-box with a .search-clear button that appears only when the input has content; clicking clears the field, re-renders immediately (no debounce wait), and refocuses. Programmatic clears (resetSearch) keep the × button state in sync — already wired into the existing empty-state "清除搜索 / 清除筛选" buttons.

Design notes

• Zero external dependencies (pure CSS/SVG/JS), consistent with the wave's constraints.
• Reuses existing semantic CSS variables so the light theme (v1.18 B) is covered automatically.
• wireSearch binds both the debounced render and the clear button in one place, keeping the four search boxes consistent.

Verification

• node --check on app.js / data.js ✓
• DOM-stub smoke test (25 assertions): debounce coalescing, <mark> highlight + clearing, × button show/hide/sync, empty-state reset paths for market & dept, operator email highlight ✓
• cargo test ✓ · cargo fmt --check ✓

Rant (verbatim)

D. 搜索增强

• 市场搜索输入防抖（~150ms，避免每次按键整表重绘闪烁）
• 搜索结果中匹配关键词高亮（<mark> 样式，accent 背景），重置后清除
• 搜索框加「清空 ×」小按钮（有内容时显示）

Docs

• docs/user-stories.md v1.18 entry extended with item D (remaining E–G noted)
• ui/README.md: new "搜索增强约定" section + page-list mentions updated