libtest has no skipped status and hides the output of passing tests, so a
test that returns early without a GPU, a corpus file, a craft-fonts face or
a model passed silently. `lightcraft-testkit` (the testkit slot the layering
table already reserves, dev-dependency only, std only) adds
`skip!(Need, "reason")`: it prints the note as before and, when
LIGHTCRAFT_SKIP_LOG names a file, appends one JSON line (need, reason, test,
binary, file:line). Plain `cargo test` is unchanged. The 61 existing skip
sites use it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
