v4.1.1

References and comments only — no code or format change from v4.1.0.

• Commit hashes cited in source, docs and the tape-work skill now point at the rewritten history.
• Comments state the reasoning for decisions instead of attributing them.
• The compat baseline test no longer leaks a temp tree when a baseline fails to build.
• docs/format-design.md §4 records the deletion gate and the 2026-09-21 round-trip measurements.