`local_art_bytes_is_confined_and_image_only` and `posix_local_art_is_classified_and_proxied`
built their `file://` values as `format!("file://{path}")`. On Windows that yields
`file://C:\covers\cover.png`, whose authority is `C:` — a UNC reference, not a local
file — so the read half failed on the box and the host suite was red there.
The parser is right and the tests were wrong: `@punktfunk/plugin-kit/library`'s `fileUrl`
emits `file:///C:/covers/cover.png` (three slashes, forward separators) and
`file_url_to_path` documents exactly that. A shared `file_url` helper now builds the value
the way the kit does, so both tests exercise the real plugin contract on both platforms
rather than a shape no plugin ever sends.
Found while gating the Playnite launch kinds on .173 — Linux CI never compiles these arms,
so the failure had gone unnoticed. Test-only: no product code changes.
enricobuehler
dd20a17edb