fix(recycling): skip render stack entries without a layout

[teoarjun]

Description

Fixes #2440

ViewHolderCollection reads every render stack entry through the throwing getLayout accessor, so an entry that outlives a layout-table shrink crashes the render with index out of bounds, not enough layouts.

RecyclerViewManager.modifyChildrenLayout truncates the layout table on its first line, but the render stack is only pruned on some of its exit paths. When the engaged range is unchanged, recomputeEngagedIndices() returns undefined and RenderStackManager.sync() never runs against the new data length, leaving keys that point past the last layout.

This routes the render path through the existing tryGetLayout accessor and skips entries that have no layout, matching the bounds-safe pattern StickyHeaders already uses. Stale entries are dropped until the next sync restores the pairing.

Reviewers' hat-rack 🎩

• The guard sits in the render loop rather than at the source. Pruning the render stack inside modifyChildrenLayout would address the stale state directly, but reaches into the engaged-indices path — happy to take that route instead if you'd prefer it.
• src/__tests__/ViewHolderCollection.test.tsx is new. It renders a stack holding indices 0-24 against a layout table truncated to 10 and asserts only the 10 live entries render; it fails without the fix, rendering all 25.

Verified locally on the branch: 201 tests pass across 16 suites, tsc --noEmit clean, eslint clean.

Screenshots or videos (if needed)

Not applicable — no visual change; the fix prevents a render-time crash.

[teoarjun]

I have signed the CLA!