Hold the store tests' modules as the settle time did, and fault a dip after any healthy reading

Two tier tests relied on the two-minute settle to keep a module unjudged; the
witness window and the gate's spacing now hold it. A healthy reading taken
before the controller's floor counted no pass, so a dip after it did not take
the two-minute pass away (novox/hq ADR 0352 decision 3).

cmd/mesh-controller/gate.go

@@ -830,11 +830,11 @@ func tallyGate(g *inventory.PlanGate, j gateJudging, now time.Time) {
 	case worst == healthWaiting:
 		// Waiting on a provider that is unhealthy: not a pass, and not a failure at the bound either —
 		// the provider's own condition says what is wrong (ADR 0240 rule 5).
-		g.Faulted = g.Faulted || g.Passes > 0 // not healthy after a healthy reading; before one, still starting
+		g.Faulted = g.Faulted || g.HealthySeen // not healthy after a healthy reading; before one, still starting
 		g.Passes, g.LastPass, g.Last, g.Failing = 0, nil, why, failing
 		g.Read(now, false, why)
 	case worst == healthNotYet:
-		g.Faulted = g.Faulted || g.Passes > 0 // not healthy after a healthy reading; before one, still starting
+		g.Faulted = g.Faulted || g.HealthySeen // not healthy after a healthy reading; before one, still starting
 		g.Passes, g.LastPass, g.Last, g.Failing = 0, nil, why, failing
 		g.Read(now, false, why)
 		if pastBound {
@@ -842,6 +842,7 @@ func tallyGate(g *inventory.PlanGate, j gateJudging, now time.Time) {
 		}
 	case now.Before(floor):
 		// Healthy before its rule lets a reading count: not a pass yet, and not a fault (novox/hq ADR 0351).
+		g.HealthySeen = true
 		// The bound still holds: a module that cannot be read healthy after its floor fails at it.
 		g.Last, g.Failing = fmt.Sprintf("healthy, and a reading counts from %s by %s",
 			floor.UTC().Format(time.RFC3339), said), nil
@@ -850,6 +851,7 @@ func tallyGate(g *inventory.PlanGate, j gateJudging, now time.Time) {
 		}
 	default:
 		// Healthy, or waiting for a person (ADR 0254): a pass, the wait carried along in the verdict.
+		g.HealthySeen = true
 		g.Passes++
 		g.LastPass, g.Last, g.Failing = &now, "", nil
 		g.Read(now, true, "")