Hold a leaf delivery to three minutes (hq ADR 0304 decision 4, issue 525)

ADR 0304 lowered a leaf module's delivery budget from five minutes to
three, the time its measured phases support once a leaf is judged on
one reading and waits only for what it shares.

cmd/mesh-controller/over_budget.go

@@ -17,8 +17,8 @@ import (
 
 // A delivery over its budget is loud (novox/hq ADR 0282 decision 7, issue 382): the self-check reads
 // mesh-delivery's `times` and raises the warning `delivery.<class>.over-budget` when the newest delivery of a
-// class whose delivery time is known took longer than its class's budget — five minutes for a leaf module, ten
-// for a core module — naming the delivery and its longest phase. It clears when the next delivery of that class
+// class whose delivery time is known took longer than its class's budget — three minutes for a leaf module (ADR
+// 0304 decision 4), ten for a core module — naming the delivery and its longest phase. It clears when the next delivery of that class
 // lands within its budget. Measurement only: the condition says, it never holds or acts on a delivery.
 
 // probeBudgetsID is the probe that reads the delivery times.
@@ -27,8 +27,9 @@ const probeBudgetsID = "D16"
 // kindOverBudget is what a delivery over its class's budget raises.
 const kindOverBudget = "over-budget"
 
-// deliveryBudgets are the budgets by class (ADR 0282 decision 1); the probe raises nothing for another class.
-var deliveryBudgets = map[string]time.Duration{inventory.ClassLeaf: 5 * time.Minute, inventory.ClassCore: 10 * time.Minute}
+// deliveryBudgets are the budgets by class (ADR 0282 decision 1, the leaf's as ADR 0304 decision 4 changed it);
+// the probe raises nothing for another class.
+var deliveryBudgets = map[string]time.Duration{inventory.ClassLeaf: 3 * time.Minute, inventory.ClassCore: 10 * time.Minute}
 
 // timesAnswer is what mesh-delivery's `times` answers, as far as the probe reads it.
 type timesAnswer struct {