Pre-release Codex regression gate caught that _normalizeArtifactPath()
did not strip ./ or ~/ prefixes, so a tool arg recorded as ./foo.md did
not match a file-tree-opened foo.md in _turnMutatedPreviewPaths — the
open preview was left stale after an agent edit via a ./-prefixed path.
Strip ~/ and leading ./ before ignore/membership checks. Node-driven
regression test pins foo.md == ./foo.md == ~/foo.md and confirms the
existing ignore-dir / URL / empty rejections still hold.
Co-authored-by: Pamnard <pamnard@users.noreply.github.com>
