## Why
Matches in parent directory names can crowd matching filenames out of limited search results. For example, searching for `ViewModel` should keep `ChatViewModel.kt` visible even when many directories are named `viewmodel`.
## What changed
- Rank basename matches before applying the result limit for single positive fuzzy queries without path separators.
- Prefer exact filenames, then the strongest exact directory match, then other matching filenames. Leave additional directory matches ranked by their paths.
- Compute highlight indices from the basename for promoted results and return scores that reflect the new ranking.
- Rank snapshots in resumable time slices so new queries and cancellation can interrupt the work.
## Testing
Add regression coverage for filename matches surviving the result limit, exact file and directory priority, path queries, and resuming partial rankings. Update app-server score expectations while preserving highlight indices.
GitOrigin-RevId: 41b3420581b4f6490859e809245370b737889544
Omer Strulovich
0327a3ec34