operations.dart carried a full second git operation surface
(gitStage/gitCommit/gitStash/gitPush/...) that duplicated GitClient
verb-for-verb, was kept alive only by its own tests, and hid a latent
pipe deadlock in _applyPatch (stdin written without draining stderr).
The file keeps the genuinely shared plumbing — gitBin resolution,
GitException, validateGitRef, GitLogEntry — which GitClient, the
status/diff readers, and the git command handlers consume.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>