Add "Coroutines vs Callbacks" page Companion to the state-machine page: why the .thenValue -> co_await lift is more correct, not just prettier. Covers the surface-area reduction (O(call sites) -> O(awaitable impls)), the bug classes coroutines delete by construction (lifetime, type, exactly-once, error propagation, RAII across the await), and the ones they pointedly don't (shared-state, affinity). Grounded in vol_io_guard, sgs_keepalive, detach, and the ublk war story. Linked from Home + Sidebar.

szmyd committed Jun 9, 2026