tsc-ts 0.0.8's API server serves on the named pipe the Node host
connects over on Windows (tsc-ts --api --pipe), and the native compiler
already starts it over its standard streams there, so tsc-ts is the
default checker on every platform. SCRIPTC_CHECKER=tsgo still selects
tsgo.
The compiler depends on tsc-ts 0.0.8, which the release-age exclusions
admit with its platform packages and @scriptc/threads 0.4.2.
The Windows CLI smoke test runs with both checkers, and
verify-native-cli.mjs --run checks that a distribution's tsc-ts runs on
its platform (tsc-ts.exe on Windows).