Pause blocking, blocked clients and a blocked line in the statistics, compact view picker

jarl block pause|resume (and the Blocking page) lets every name through
for a while; jarld resumes on time. The lists stay loaded: the rules zone
just passes everything. Statistics gain the clients with the most blocked
queries and blocked queries on the queries chart. The view choice in the
blocking forms is a dropdown.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/stats/collector.go

@@ -24,10 +24,12 @@ const (
 	KindServFail = "servfail" // names answered with SERVFAIL
 	KindRefused  = "refused"  // clients that were refused
 	KindBlocked  = "blocked"  // names blocked (docs/blocking.md)
+	// KindBlockedClient: clients with the most blocked queries.
+	KindBlockedClient = "blocked_client"
 )
 
 // Kinds lists the top-list kinds.
-var Kinds = []string{KindName, KindClient, KindNXDomain, KindServFail, KindRefused, KindBlocked}
+var Kinds = []string{KindName, KindClient, KindNXDomain, KindServFail, KindRefused, KindBlocked, KindBlockedClient}
 
 // OtherZone is the zone key for names outside every local zone (answered
 // by recursion, or refused).
@@ -380,6 +382,7 @@ func (c *Collector) handleRewrite(rw Rewrite) {
 	}
 	hours[hour] = c.hourMaps(hours, hour)
 	hours[hour][KindBlocked][rw.Name]++
+	hours[hour][KindBlockedClient][clientKey(rw.Client, c.opts.Anonymize)]++
 }
 
 // policySource names what a rewrite came from: a blocklist's name, "rules"