Admin: leases, pin, release, drain, usage, metrics

cmd/crossbar/main.go calls admin.Handler with the new 6-arg signature, passing nil for the not-yet-wired leases/limiter/store/drainer (task 07 wires them) so go vet and go test ./... pass on cmd/crossbar. This is a compile fix, not the task-07 wiring; noted in the implementer-log.

Implemented-By: OpenCode session (model recorded in docs/implementer-log.md)

internal/store/schema.go

@@ -141,6 +141,18 @@ func scanUsage(rows *sql.Rows) ([]UsageRow, error) {
 	return out, rows.Err()
 }
 
+func scanStatusCounts(rows *sql.Rows) ([]StatusCount, error) {
+	var out []StatusCount
+	for rows.Next() {
+		var c StatusCount
+		if err := rows.Scan(&c.Route, &c.Host, &c.Status, &c.Count); err != nil {
+			return nil, wrap(err)
+		}
+		out = append(out, c)
+	}
+	return out, rows.Err()
+}
+
 func scanEvents(rows *sql.Rows) ([]LeaseEvent, error) {
 	var out []LeaseEvent
 	for rows.Next() {