When a task branch adds ignore rules for a path that was untracked in the
user's stashed WIP, a failed stash pop can restore the file and then leave it
hidden from normal status after reset. Default `git clean -fd -- <path>` does
not remove ignored files, so the partial restore could still leak into later
isolated task baselines.
Add an includeIgnored clean mode and use `git clean -fdx -- <stash path>` for
failed stash-pop cleanup. Extend the fallback regression so the task branch adds
.gitignore for the restored untracked path and verify both normal and ignored
status return clean.
Fixes#4175
roboomp
4d471b1aa4