What changed? Why?

Makes the CDS cds-mobile chart render a lightweight, static line when it isn't animating — with no new public API. The win rides on the existing animate prop plus an internal ScrubberProvider optimization:

• Path static branch (the clip win). Path now delegates to a reanimated-free StaticChartPath when the chart isn't animating (animate={false}, which is also what non-interactive charts want). It clips with an axis-aligned rect (routed to canvas.clipRect, a GPU scissor) instead of the anti-aliased path clip (Skia.Path.addRect() → canvas.clipPath) that falls back to Skia's CPU SoftwarePathRenderer. The animated branch is unchanged.
• ScrubberProvider (the scrubber win). When enableScrubbing is false (the default), the provider now skips the pan gesture and the useAnimatedReaction allocation entirely (split into enabled/disabled providers). Every non-scrubbing chart benefits, not just a special mode.
• ReferenceLine strokeWidth. New prop so callers can size the reference line (previously fixed at the line component's default).

Why: non-interactive row sparklines in scrolling lists pay a main-thread Skia cost from the anti-aliased path clip when many rows recycle. consumer/react-native #73650 worked around it with a bespoke LightweightSparkline; per the reviewer's comment the clean long-term fix is a static mode on the CDS chart so callers get the win without a bespoke component. This delivers that via existing props.

Note (review outcome): an earlier revision added an interactive prop. Per review, that was dropped — scrubbing is already opt-in via enableScrubbing and animation via animate, so the lightweight render is reached with animate={false} and the ScrubberProvider efficiency improvement, with no new API surface.

Consumer migration (follow-up PR, after release): replace <LightweightSparkline …/> with <LineChart animate={false} …> + <ReferenceLine dataY={…} />, then delete the bespoke component.

Linear: https://linear.app/coinbase/issue/APP-770

Root cause (required for bugfixes)

N/A — performance feature, not a bugfix. (The cost is the anti-aliased path clip → SoftwarePathRenderer; a rect clip is a GPU scissor and preserves bounds, so curve="bump" overshoot cannot bleed out.)

UI changes

No visible change to animated (default) usage — the animated render path is untouched. animate={false} renders the line identically at rest (the rect clip preserves the same bounds as the previous path clip); it only drops the entrance-reveal animation. A new "Lightweight (Static)" LineChart story variant was added (data crossing a dotted ReferenceLine) so the mobile visreg target (apps/expo-app) captures it.

iOS Old	iOS New
no change to animated usage

Android Old	Android New
no change to animated usage

Captured on the iOS simulator and Android emulator running the new "Lightweight (Static)" LineChart story (animate={false}); visual parity is also covered by the story + visreg.

Testing

How has it been tested?

• Unit tests
• Interaction tests
• Pseudo State tests
• Manual - Web
• Manual - Android (Emulator / Device)
• Manual - iOS (Emulator / Device)

Testing instructions

• chart/__tests__/Path.test.tsx: asserts the static branch clips with a rect (canvas.clipRect) not an SkPath, honors an explicit clipPath, and that the animated path is still used when the chart animates.
• chart/scrubber/__tests__/ScrubberProvider.test.tsx: asserts the pan gesture + useAnimatedReaction are set up when enableScrubbing is true and skipped when it's false.
• chart/line/__tests__/LineChart.test.tsx: smoke-renders an animate={false} chart.
• Full mobile chart suite green (356 tests), typecheck, lint (0 errors), format all pass.
• Guards flip red if their part of the diff is reverted.

Residual / follow-up (not addressed here): in the static case useChartLayout's rAF measure→setState double render and the full scale/domain recompute still run, so this is lighter than the bare LightweightSparkline but not equivalent. consumer/react-native should confirm with a native trace before removing its kill switch.

Illustrations/Icons Checklist

N/A — no changes under packages/illustrations/** or packages/icons/**.

Change management

type=routine
risk=low
impact=sev5

automerge=false