Keep each walk's phases and say a delivery over its budget (hq ADR 0282 slice 1, issue 382)

The operator's budget (a leaf module running everywhere within five minutes
of its merge, a core module within ten) cannot be held to without knowing
where a walk's time goes. A walk now keeps when its batch's window closed,
when it was cut and its class (migration 0093), each gate reading, and what
each machine of the rest was sent; 'delivery walks' and plan-moved say its
phases from the merge to every machine of the rest reporting the build
applied, and ended walks keep them as walk-phase durations per class. Probe
D16 reads mesh-delivery's 'times' and raises delivery.<class>.over-budget.
A phase that cannot be measured is said unknown, never zero. Measurement
only: no walk is held, sent or judged differently.

cmd/mesh-controller/main.go

@@ -311,7 +311,7 @@ func usage() {
                                  the self-check: the last verdict, a run now, the probes, the signals' ages
   healers [--days N] [--json]    the healers, what they did lately, and their brake (to-be 45 §7)
   durations [--kind K] [--days N] [--json]
-                                 apply, heartbeat, plan-tier and build durations, per machine or module
+                                 apply, heartbeat, plan-tier, build and walk-phase durations
   collection [--json]            kept archives held/unheld by a manifest, and what the sweep may let go
   builder issue <name>           a broker account for a build machine, scoped to build work,
                                  delivered as the builder module's broker secret (module add it first)