quiesce

The dirty signal Zin.tick's quiescence gate reads. A mutation of the mapping layer's structure outside the tick itself — a map activation, a context change, a virtual-control write, a forced surface class, a new axis over an already-held key — calls mark(), and the tick runs a full pass while a mark is pending. A tick with no pending mark and no live input events skips its pass.

mark() raises the signal, pending() answers whether a full pass is owed, and the generation pair (generation() / ack(g)) keeps a mark raised DURING a full pass pending for the next one, so a mutation racing a tick is never lost.

Internal to the zinput package: the mapping-layer modules mark it, the tick drains it.