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/engine/diffops.go

@@ -17,6 +17,9 @@ func DiffOps(from, to *model.State) []model.Op {
 	add := func(kind string, id int64, base int, data any, summary string) {
 		ops = append(ops, newOp(kind, id, base, data, summary))
 	}
+	if !reflect.DeepEqual(from.Settings.BlockingPausedUntil, to.Settings.BlockingPausedUntil) {
+		add(OpBlockingPause, 0, 0, BlockingPauseInput{Until: to.Settings.BlockingPausedUntil}, map[bool]string{true: "pause blocking", false: "resume blocking"}[to.Settings.BlockingPausedUntil != nil])
+	}
 	if !reflect.DeepEqual(stripVersion(from.Settings), stripVersion(to.Settings)) {
 		s := to.Settings
 		add(OpSettingsUpdate, 0, 0, SettingsInput{DefaultTTL: &s.DefaultTTL, Nameservers: model.Ptr(append([]string{}, s.Nameservers...)), RName: &s.RName,
@@ -184,6 +187,7 @@ func DiffOps(from, to *model.State) []model.Op {
 
 func stripVersion(s model.Settings) model.Settings {
 	s.Version = 0
+	s.BlockingPausedUntil = nil // its own operation
 	return s
 }