fix(scrollview): honor programmatic scrollTo when scrollEnabled={false}

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Problem

On a ScrollView/FlatList with scrollEnabled={false}, imperative scrollTo / scrollToOffset / scrollToIndex do nothing on RNW. On iOS/Android, scrollEnabled blocks only user gestures — programmatic scrolls still apply.

Root cause

ScrollViewComponentView::scrollTo() early-returns when scrollEnabled is false. scrollToIndex/scrollToOffset route through the scrollTo command, so all imperative scrolls are dropped.

Fix

Remove the early-return. User-gesture scrolling remains gated by m_scrollVisual.ScrollEnabled(...) (set from scrollEnabled in updateProps), so this only re-enables programmatic scrolls — matching iOS/Android semantics.

Validation

Bug reproduced in a production RNW 0.83.2 new-arch app (Facilitron FIT, Windows 11 ARM64, Debug, 250% scale): a scrollEnabled={false} ScrollView with 800-DIP content in a 110-DIP viewport ignores scrollTo({y:500, animated:false}) — the call fires, no scroll event is emitted, content stays at Row 0. The probe renders its own status line:

Expected after-state per the diff: TryUpdatePosition applies the offset and onScroll reports y=500. Needs upstream CI + the same probe on a framework source build.

Intentionally not touched: StartBringIntoView() and scrollToEnd()/scrollToStart() carry an analogous gate but also serve keyboard/focus paths — changing those would alter keyboard-scroll semantics, so they're flagged for maintainer discussion instead. Authored against 0.83-stable; happy to re-cut onto main.

Microsoft Reviewers: Open in CodeFlow

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@microsoft-github-policy-service agree [company="Facilitron"]

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@microsoft-github-policy-service agree company="Facilitron"

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Validated end-to-end on a patched framework source build. We compiled this fix into Microsoft.ReactNative from source (yarn-patch, RNW 0.83.2, ARM64 Debug; patched dll verified as the loaded module via GetDeviceCaps/GDI32 import markers vs the stock NuGet dll as negative control) and re-ran the same probe in our production app: scrollTo({y:500}) on a scrollEnabled={false} ScrollView now applies — status line reads "onScroll y: 500" with the y=500 row at viewport top (previously "none", content parked at Row 0).

Before:
After: