Review round 1 of the refusal contract: it claimed more than it held.
- The other reason carriers get their Literal too (BlockedUrl, ClipError,
FolderError, the playlist and sign-in refusal helpers), so the type
checker refuses a reason passed by variable or an unknown literal, and
the contract reads one shape.
- A literal reason in a detail dict built anywhere counts as a reason of
its code; a code the scan cannot read, a refused() whose reason it
cannot read, and a new reason passed by variable each fail the contract
until listed with what holds them.
- A sign-in refusal key the backend no longer sends is caught too.
- localizeDetail's numbers (download cap in GB, upload cap in bytes) and
the shared-sentence fallbacks are tested in both languages.
- One Literal parser in the contract; a stale comment fixed.