An idle StarshipOS kept a CPU core 100% busy: sk_v4_readline(), with
nothing typed, and sk_v4_identity_wait(), headless until Zuse, waited in
arch_relax(). Both now halt until the next interrupt (hlt; wfi on aarch64
and riscv64): the heartbeat's timer, ISR-driven on all three, wakes them at
100 Hz, so a key is still seen within a tick.
Idle at the prompt, QEMU's CPU: 100% -> 1% of a core on amd64, 1% on
aarch64 and riscv64. Acceptance passes: amd64 logs/20261108-005539, aarch64
-005753, riscv64 -010136 (POST 538/538, one dict_hash, 7 ok), the stick
loaded high, test-32 (39 programs, 0 failures). FABRIC-3 XLVIII.5.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GE3SDvQn5EoxdGufk84zz2
