Repository API endpoints
## Overview
Expose a set of new REST API endpoints that map directly to Gitaly RPCs, enabling AI agents and other API consumers to interact with Git repositories without requiring a GitLab project context.
Each endpoint is gated behind the `repository_api` Premium licensed feature.
promoted from : https://gitlab.com/gitlab-org/gitlab/-/merge_requests/233900
## Endpoints
1. `GET /projects/:id/repository/search/files_by_content` — SearchFilesByContent
2. `GET /projects/:id/repository/search/files_by_name` — SearchFilesByName
3. `POST /projects/:id/repository/blobs/batch` — GetBlobs
4. `GET /projects/:id/repository/changed_paths` — FindChangedPaths
5. `GET /projects/:id/repository/ancestor` — CommitIsAncestor
6. `GET /projects/:id/repository/diverging_commits` — CountDivergingCommits
7. `GET /projects/:id/repository/files/:file_path/last_commit` — LastCommitForPath
8. `GET /projects/:id/repository/tree_commits` — ListLastCommitsForTree
9. `GET /projects/:id/repository/diff_stats` — DiffStats
10. `GET /projects/:id/repository/commits/search_by_message` — CommitsByMessage
epic