[EraPartner]

Requested by EraPartner · project thread

Summary

Tor reported that dragging across a chart after clicking a point no longer shows the price change. A Playwright check on main showed that press-and-drag still worked on the charts that had scrubbable turned on. The security price charts (watchlist dialog, market lookup, research compare, chart builder) never had it, and release cleared the result straight away. This PR:

• Gesture (scrub.ts): one reducer supports both readings of "click, then drag".
  • Press, drag and release in either direction. The range stays on screen after release.
  • Click, move and click: the first click anchors a point, the range follows the pointer, and the second click pins it.
  • A click on a pinned range, Escape, a plain arrow key, blur, or leaving the chart clears it.
• Overlay (ScrubOverlay.tsx): the band is tinted gain or loss and has edge hairlines and value dots at both ends. The readout shows the period and Δ (absolute and %) for every series and stays inside the chart box. Before, only series[0] was shown, which on the portfolio hero chart is the dashed "invested" line.
• ComposedChart gains scrubbable.
• Turned on for WatchlistChartDialog, MarketLookupPage, ResearchComparePage, ChartBuilderPage (main chart) and PortfolioForecastPage. Statistics flow charts, the oscillator and AI tool charts stay off.
• A click on a chart no longer draws the browser's default black focus outline. Keyboard focus keeps the house ring.
• Shortcut tip (en/nl) and docs (docs/components/charts.md, docs/reference/code-patterns.md, docs/architecture/frontend-architecture.md) are updated.

Type of change

• feat — new feature

Checklist

• Types check (tsc -p tsconfig.app.json)
• Lint clean on changed files (one pre-existing warning in StackedBarChart)
• Conventional Commit title
• Affected docs/ pages updated
• i18n: validate-locales passes

Architecture & data

• No architectural change
• No API change
• No schema change

Verification

• New boundary tests in chartScrub.test.tsx cover both drag directions, the pinned result, click to clear, click-move-click, Escape and leave, the not-scrubbable case, and Line and Composed charts. Chart suite: 8 files, 48/48 pass.
• Full frontend vitest: 3829 passed, 4 failed. All 4 failures are in CSV encoding tests (useCsvPreview, FileHeadersPanel, PortfolioCsvColumnMapper), which expect windows-1252 € and get \u0080. That points to the container's ICU, and this PR touches none of those files.
• Playwright against a Vite harness, not committed: drag R→L, release keeps the readout, a click dismisses it, click-move-click pins, and Escape and leave clear.

Residual risk & follow-ups

• Not run in the packaged Electron app on the Mac.
• With 5 or more series, the readout shows 4 rows and then "+N".

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Generated by Claude Code

[github-actions]

Coverage Report for backend

Status	Category	Percentage	Covered / Total
🟢	Lines	91.07% (🎯 80%)	23182 / 25455
🟢	Statements	89.33% (🎯 78%)	24949 / 27926
🟢	Functions	91.45% (🎯 76%)	5010 / 5478
🟢	Branches	81.62% (🎯 68%)	17492 / 21431

File Coverage

No changed files found.

Generated in workflow #1966 for commit 059ac92 by the Vitest Coverage Report Action