Module sync::thread_bare

Freestanding Cooperative Threads Priority-aware wrapper over TaskScheduler. Freestanding-safe.

Thread functions use the same coroutine protocol as TaskScheduler:

int func(?&T arg, int resume_point)
Returns > 0 to yield (value = new resume_point), 0 when done.

Threads with higher priority values run before lower-priority ones within each scheduling tick.