comment #341
W10 implementation handed to doyle's gate. Branch fix/341-busy-window-axis at 89fd4412 (spt-bs-core), also fixes #256.

What changed: both hook drains no longer read the rest record, so a dormant (unwatched) endpoint drains its busy-window messages on its own poll. The away notice now reaches the agent while it is away, and the return notice can only follow it. A suspended endpoint receives them on its first poll after waking. The send flag is now spelled busy-only; the old active-only and deferred spellings keep parsing, hidden.

Evidence: a new two-arm integration test drives the real away/return producer and the real binary. It passes on the branch, and it fails at its tagged assertion (left 0, right 2) when the old gate is put back. CONTEXT.md and the messaging, instances and lifecycle docs are updated.