ben zhang 48b6a9d8e0 Reserve a sibling rollout candidate slot for the first ancestor (#55627) ...

## Why

Sibling rollout prefetching returns no paths when its candidate set omits the first ancestor. With more than 64 sibling rollouts, the candidate limit could exclude that ancestor and prevent prefetching.

## What changed

Pass the first ancestor ID into candidate collection and reserve the final slot for it until it is found, preserving the 64-candidate limit.

## Testing

Add a regression test that creates more siblings than the candidate limit and verifies that an otherwise omitted ancestor is included when prioritized.

GitOrigin-RevId: 130508dfb1a190af68ccf1911c7501617be79a00

2026-10-20 16:40:36 +00:00

..

src

Reserve a sibling rollout candidate slot for the first ancestor (#55627)

2026-10-20 16:40:36 +00:00

BUILD.bazel

Extract rollout into its own crate (#15548)

2026-03-24 18:10:53 -07:00

Cargo.toml

Preserve rollout access metadata across compression and restoration (#55252)

2026-10-19 11:02:40 +00:00