feat(ui): transactions summary bar — income/expense/net tied to tab & column filters (v1.19 B)

[argszero]

Summary

UI/UE 4th-round deepening — item B: transactions summary bar (rant 2026-08-17T20:39:30, v1.19).

A compact inline summary bar (#tx-summary, .tx-summary) now sits at the top of the transactions card (above the table), showing 总收入 / 总支出 / 净变化 — positive + green (var(--ok)), negative - red (var(--danger-text)), zero rendered neutrally as 0. No new layout: three inline stat columns inside the existing card.

• Tied to the tab filter (全部 / 消费 / 收益) — switches recompute instantly
• Consistent with column filters: extracted the table's filter logic into a shared filterRows(rows, columns, filters) used by both buildDataTable and the summary, so the summary always reflects the same filtered set as the visible rows (unaffected by pagination)
• Responsive: narrows gap/font on ≤560px, flex-wrap fallback

Docs: docs/user-stories.md v1.19 (item B) + ui/README.md「交易汇总条约定」. Verified by node --check, DOM-stub smoke test (12 assertions: all/consume/earn tabs, column-filter linkage, filter clear, pagination invariance), cargo test, cargo fmt --check.

Rant (verbatim)

Rant: UI/UE 第四轮多角度深化 — 状态保持、信息密度、原生控件美化、帮助可达性（宿主 2026-08-17 第四轮指示：继续从多角度美化 UI、优化 UE）

B. 交易记录汇总条

• 交易页顶部加一行汇总（随 tab 过滤联动）：总收入 / 总支出 / 净变化（+绿 −红），当前该页只有表格没有汇总
• 用小 stat 组件或紧凑 inline 条，不引入新布局

Related

• Rant timestamp: 2026-08-17T20:39:30.507364 (project aitokenpool, status in_progress; item A = PR feat(ui): URL hash routing — share/bookmark/refresh restore (v1.19 A) #55 merged)
• Branch: feat/ui-ue-round4-tx-summary (per rant: 分支 feat/ui-ue-round4; items C–G to follow)

Tests

• node --check ui/js/app.js
• DOM-stub smoke test — 12/12 assertions pass
• cargo test — 1 passed
• cargo fmt --check