[starc007]

What

Three new charts in the charts category, on a shared components/charts/xy/ layer.

• Line Chart (@beui/line-chart): line and area variants, monotone/linear/step curves.
  • Every sample is a spring keyed by series and category, so new data, hidden series and axis rescales morph lines, fills and dots together. Resizes snap.
  • Lines draw in on first view and fade out at the plot edges.
  • Inspecting shows a crosshair with haloed dots, recedes the line past the crosshair, and rolls a pill along the category axis.
  • The tooltip lives inside the chart and springs beside the highest value. It flips near the right edge, and on narrow plots moves above or below the point.
  • status="loading" shows a pulsing placeholder that hands off to the draw-in.
• Bar Chart (@beui/bar-chart): grouped or stacked, vertical or horizontal, sort by visible total.
  • Bars animate with transforms only, using a separate rounded cap so corners never stretch.
  • Bars grow in with a stagger, and categories glide to new ranks when sorting changes.
  • The tooltip follows the pointer, like Volume Profile's, with a soft band gliding behind the hovered category.
• Sparkline (@beui/sparkline): compact trend with an optional change badge (invertDelta for lower-is-better metrics).
  • A labelled image by default, with no tab stop.
  • interactive adds one slider and a value readout.
• Shared xy/ layer:
  • Data cleanup: first of repeated ids wins, and invalid values become gaps, never zeros.
  • Rounded ticks, curves and animated points.
  • One native-slider inspector, legend toggles, tooltip rows and a hidden data table.

Why

The catalog had specialized charts but no plain line or bar chart, which are the most common requests. Sparkline covers stat cards and tables.

Accessibility

• Each chart is one tab stop: an invisible native slider over the plot. Arrow keys, Home and End step categories, and the slider announces every visible value.
• Horizontal bars follow visual order, with Arrow Down moving down the list.
• Legend entries are pressed-state buttons.
• A visually hidden table lists every value, and gaps read as No data.
• While loading, the line chart is marked busy, announces its label, and leaves out the slider and table.
• Mouse-click focus no longer pins tooltips open after the pointer leaves. Keyboard focus and touch tap-to-inspect still hold.
• Reduced motion drops the draw-in, springs, stagger and roll, and keeps opacity changes.

Also

• Registry entries with launchedAt, previews and usage files, About and SEO copy, component dates and changelog lines.
• AGENTS.md catalog rows for all three charts.
• Previews use the library Tabs in the docs pill style.

Verification

• bun run check passes, and bun test passes 190 accessibility tests, including new tests/xy-charts.a11y.test.tsx.
• Checked in the browser:
  • Desktop and 375px mobile, with no horizontal scroll.
  • Keyboard, simulated touch drags, the loading handoff, and tooltip placement at plot edges and on narrow plots.
• Not checked visually: reduced motion, which can't be emulated in the browser pane. Those code paths are covered by review and by the tests, which render with reduced motion.