Review round 1 on PR #189 (three tests stayed green with their guard removed): - TestEditRefusesANoteBehindASymlinkedDirectory had no .git, so Edit refused "not the sync source" before any path check. It now has one, plus a positive control. - AppendRegular's unclean-path case was refused by a final symlink, not cleanRel. New test where ".." after a symlinked dir resolves to a real file, for AppendRegular and PutRegular. - brainfs.Remove had no test; new one (refuses behind a symlinked dir, removes a final link but never its target, positive control). Also: promote/reject create with O_EXCL (new brainfs.CreateRegular), so a note that appears after the collision check is never overwritten; gofmt fixes in provenance.go and wiki/log.go; dead wingDir and putBrainFile removed. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>