The list-directory handler returned { path, entries } while the
renderer typed result.data as FileEntry[]; the file-store had to fall
back to raw.entries via Array.isArray. Extract the entries builder into
src/main/files/list-directory.js so it can be unit-tested, return a
plain array, and skip entries that can't be stat'd (broken symlinks,
permission errors) instead of throwing.
Also tighten jest config so dist/*.snap electron-builder artifacts are
not matched as test suites.
