Judge a leaf module on one healthy reading, a core module on three (hq issue 524)

ADR 0282 decided readings by class and ADR 0304 took a leaf module to
one, but the gate never learned it: every build, leaf or core, needed
three readings over at least two minutes, so a container module that
was healthy at once still waited about two and a half minutes on its
first machine. The number of readings and the settle time now follow
the module's class: three after two minutes for the controller's own
path and the resolver, one for every other module. Tests that judge a
gate's other rules keep leaf modules on three readings.

internal/inventory/plans.go

@@ -302,7 +302,10 @@ type PlanGate struct {
 	Sent map[string]SentDeclaration `json:"sent,omitempty"`
 	// Passes counts the consecutive judgings that found it healthy, LastPass the newest; a judging that
 	// does not resets them.
-	Passes   int        `json:"passes,omitempty"`
+	Passes int `json:"passes,omitempty"`
+	// Wants is how many passes the send needs: a core module's three, a leaf module's one (novox/hq ADR 0282
+	// decision 4 as ADR 0304 decision 3 changed it). Zero in a gate judged before it was said: three.
+	Wants    int        `json:"wants,omitempty"`
 	LastPass *time.Time `json:"last_pass,omitempty"`
 	// Last is what the newest judging found wanting, while it still may pass.
 	Last string `json:"last,omitempty"`