expand_home() fell through to PathBuf::from(input) — the literal,
unexpanded "~/..." string — whenever the HOME env var itself wasn't set,
same bug class as breadclip-core/breadpad-shared/breadmon (found during
this pass's own crate-migration sweep, in a different shape here: the bug
was in this crate's own tilde-expansion helper rather than a
dirs::xxx().unwrap_or_else() chain). Fixed via bread_utils::xdg::home_dir,
which resolves a real home directory before ever needing to fall back.
Builds and tests clean: 205 passed, 1 pre-existing network-dependent test
ignored, 0 failed.