A plan sent every machine running a module at once, ignoring the module's
upgrade policy. Unless the policy says together, the first machine by name
is sent, recorded in the plan, and the rest follow only once its report
after the send says it applied; a failed first machine stops the plan.
A tier whose module a later tier is built by waited for the machines running it to report after the
build — and relied on the catalogue's moved event to send them. A rebuild from the same source commit is
not a move the catalogue announces: the build machine rebuilt for a controller change kept its commit,
nothing sent it, and the plan waited on a report that would never come (2026-10-01, 19:45Z). The plan
now sends the machines running a gated module once, records when, and waits for the reports after that.
A module's dependencies are one relation in the catalogue — stands-on, packages, built-by, declared —
answered by one call. A merge takes what moved and everything reachable from it, sorts the set into
tiers (a code dependency in the same tier, a build dependency after its base is built, a runtime
dependency after the build machine is built and running; the build machine's own base comes first,
built by the one that runs), writes the plan to the store, asks the first tier and returns. Every
outcome advances the plan; a ticker advances what outcomes cannot; a controller replaced mid-plan
resumes it. status lists open plans and names one that has waited too long.