stickyHeaderConfig.offset also pushes list content down, not just the sticky pin position

Description

1. stickyHeaderConfig.offset moves the sticky pin position down, which is what the docs describe.
2. But it also pushes the whole list content down by the same amount.
3. The cause: FlashList renders an internal spacer view between ListHeaderComponent and the cells and gives it marginTop: offset (viewToMeasureBoundedSize in RecyclerView.tsx, around line 508).

Current behavior

With stickyHeaderConfig={{ offset: 100 }}:

• sticky headers pin 100px from the top (correct)
• every row also shifts down 100px
• a 100px empty gap appears between ListHeaderComponent and the first row 😵

The gap also happens without ListHeaderComponent, at the top of the content. A header just makes it more visible because the gap sits in the middle of the layout.

Expected behavior

• the offset only changes where sticky headers pin
• content layout stays the same

My real case: the list sits under a translucent navbar and my ListHeaderComponent already contains a spacer for it. With offset set to the navbar height, the space is counted twice. There is no way to opt out of the content shift.

Reproduction

https://snack.expo.dev/@sbycrosz/flashlist---sticky-header

Platform

• iOS
• Android
• Web (if applicable)

Environment

pnx expo --version
57.0.10

FlashList version: 2.3.2

Additional context

PR #1953 lists "Applies marginTop spacer to content for offset alignment", so the shift looks intentional. But the docs for offset only mention the pin position, and there is no flag to keep the content in place. Either the spacer should be optional, or it should render before ListHeaderComponent so the header clears the top bar too.

Only workaround I found is patching the package to remove the marginTop.

Checklist

• I've searched existing issues and couldn't find a duplicate
• I've provided a minimal reproduction (Expo Snack preferred)
• I'm using the latest version of @shopify/flash-list
• I've included all required information above

Start in RecyclerView.tsx around viewToMeasureBoundedSize near line 508, where the issue identifies the marginTop spacer, and review PR #1953 for its intended alignment behavior. Reproduce the issue with the linked Expo Snack using stickyHeaderConfig.offset and verify that the offset still affects sticky pinning without adding a content gap or shifting list rows.