HasChangesAsync counted untracked files, so a stray file in the shared
target working dir (e.g. left by a concurrent session) blocked merge
preflights even though nothing tracked changed. Add an includeUntracked
overload defaulting to true, and pass includeUntracked: false only from
the two target-working-tree merge preflights (TaskMergeService.MergeAsync,
PlanningMergeOrchestrator.StartAsync). Auto-commit and the worktree
cleanup data-loss guard keep counting untracked files, since those
callers need to know about them.
mika kuns
14e4c086e2