feat: android charts

[DorianMazur]

Android Chart Implementation

Implements the Android counterpart to the iOS Chart component added in feat/charts. Supports bar, line, area, point, rule, and sector (pie/donut) mark types inside Glance widgets.

Approach

Jetpack Glance has no charting API, so charts are rendered to a Bitmap via Android Canvas and displayed as a Glance Image using Icon.createWithBitmap().

• ChartBitmapRenderer.kt — core Canvas drawing engine for all 6 mark types, axes, grid lines, labels, and color palette
• ChartRenderers.kt — Glance composable that reads style/props, renders the bitmap, and outputs an Image
• ChartParameters.kt — generated parameter model

Chart dimensions come from the style prop. Bitmaps are capped at 600px to stay within RemoteViews parcel limits.

TypeScript

• VoltraAndroid.Chart and mark components (BarMark, LineMark, AreaMark, PointMark, RuleMark, SectorMark) in the Android namespace
• Shares types and wire format with the iOS Voltra.Chart from feat/charts

Example app

• AndroidChartWidget.tsx — 4 widget variants (bar, line, area, pie)
• AndroidChartScreen.tsx — interactive preview with chart type and size selectors

Bar	Line	Area	Pie

• Widget registered as chart_widget in app.json with initial state

[vercel]

@DorianMazur is attempting to deploy a commit to the Callstack Team on Vercel.

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[Angelk90]

@DorianMazur : Great work, you can post videos of them in use on the home.

When I run:
npx expo prebuild --platform=android

In voltra/example, i get:

✖ Prebuild failed
Error: [android.dangerous]: withAndroidDangerousBaseMod: Failed to prerender widget state for 
chart_widget (./widgets/android-chart-widget-initial.tsx): Unsupported element type "undefined".
Report this as a bug in the Voltra project.