manifest.py::_sha256 does an unguarded open(). check_modified() and
uninstall() both call it on a readable-but-unopenable regular file
(e.g. permission denied) without catching OSError, so
'specify integration upgrade/uninstall/switch' surface a raw
PermissionError traceback. Guard both call sites: in check_modified()
treat an unreadable file as modified (consistent with the adjacent
symlink / non-regular-file handling); in uninstall() treat it as skipped
and preserve it (mirroring the existing path.unlink() OSError guard just
below). The force short-circuit is unchanged.
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
10d4bca64c