iox v0.3.0 — Adaptive back-off for external I/O waiting
Added
iox.Backoff: Adaptive back-off for external I/O waiting. Zero-value is ready-to-use with sensible defaults (500µs base, 100ms max). Implements linear block-based scaling with ±12.5% jitter to prevent thundering herds. Part of the Three-Tier Progress model: Strike (syscall) → Spin (atomic) → Adapt (I/O readiness).