Windows preserves the user-typed `/` when Path::join() ingests a multi-
component string with forward slashes, producing a mixed-separator path
in the rendered <file> block (e.g. `C:\...\.tmpKxj0Pk\nested/deep/file.md`).
The test compared full paths via display(), which mismatched.
Switch to a basename comparison per CLAUDE.md's portability rule.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Hunter Bown
693fbca4ea