Report a provider that keeps failing a consumer in status (hq ADR 0224)

The identity provider failed every consumer for a day and status called the
mesh well (hq issue 179). The controller now follows every provider's
provisioner.failing/recovered, keeps the newest failing word per provider,
machine and consumer (migration 0065), and status, its JSON and node show
name it until it recovers. Every module that receives contributions is
granted the two events, so no manifest can forget them.

cmd/mesh-controller/build.go

@@ -676,6 +676,9 @@ type answers struct {
 	// refused, until the switch — and while there is any, the mesh is not all well: the order the
 	// machines' modules are built in is the mesh's to keep, and this is where it says it is not kept.
 	unheld []catalogue.Unheld
+	// failing is every consumer a provider says it keeps failing (novox/hq ADR 0224): a provider's
+	// journal was the only place that said so for a day (04-ISSUES/179).
+	failing []inventory.ProviderStanding
 }
 
 // heldBy is every artifact this mesh has built, for a build that may need one as its base.