The plans verb: what the last merges produced and where each stands (hq ADR 0162)

The mesh's seat answers plans — the recent plans with their tier, what each waits for and since when,
or one plan whole given its id — so the console reads a merge's progress where it reads everything
else, instead of a person reading the daemon's log.

cmd/mesh-controller/main.go

@@ -72,6 +72,8 @@ func run() error {
 		return askCommand(ctx, args[1:])
 	case "builds":
 		return buildsCommand(ctx, args[1:])
+	case "plans":
+		return plansCommand(ctx, args[1:])
 	case "pin":
 		return pinCommand(ctx, args[1:], true)
 	case "unpin":