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/blocking_test.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 	"sync/atomic"
 	"testing"
+	"time"
 
 	"jarl/internal/blocking"
 	"jarl/internal/model"
@@ -229,3 +230,54 @@ func TestBlocklistRefresh(t *testing.T) {
 		t.Error("the deleted list's status is still there")
 	}
 }
+
+func TestBlockingPause(t *testing.T) {
+	env := newEnv(t)
+	setupZone(env)
+	env.submit(env.admin, blocklist("ads", "https://example.org/list"))
+	rulesFile := filepath.Join(env.dir, "zones/_default/rules.jarl.invalid.rpz")
+	if _, err := os.Stat(rulesFile); !os.IsNotExist(err) {
+		t.Fatal("a rules zone without rules or a pause")
+	}
+	until := env.e.Now().Add(10 * time.Minute)
+	res := env.submit(env.admin, NewRequest(OpBlockingPause, 0, BlockingPauseInput{Until: &until}))
+	if !strings.HasPrefix(res.Ops[0].Summary, "pause blocking until ") {
+		t.Errorf("summary = %q", res.Ops[0].Summary)
+	}
+	f, err := os.ReadFile(rulesFile)
+	if err != nil || !strings.HasSuffix(string(f), "NS\tlocalhost.\n*\tCNAME\trpz-passthru.\n") {
+		t.Fatalf("paused rules zone: %v\n%s", err, f)
+	}
+	conf, _ := os.ReadFile(filepath.Join(env.dir, "etc/named.conf"))
+	if !strings.Contains(string(conf), "zone \"rules.jarl.invalid\" min-update-interval 0 log no;\n\t\tzone \"ads.") {
+		t.Errorf("the paused rules zone must come first:\n%s", conf)
+	}
+	// Not yet time: nothing happens.
+	if got := env.e.ResumeBlocking(context.Background()); !got.Equal(until) {
+		t.Errorf("ResumeBlocking before the end = %v", got)
+	}
+	// Time is up: resumed, and the rules zone is gone again.
+	env.submit(env.admin, blockRule("ads.example", "block", false))
+	env.e.Now = func() time.Time { return until.Add(time.Second) }
+	if got := env.e.ResumeBlocking(context.Background()); !got.IsZero() || env.state().Settings.BlockingPausedUntil != nil {
+		t.Fatalf("after the pause: %v, %v", got, env.state().Settings.BlockingPausedUntil)
+	}
+	if f, _ := os.ReadFile(rulesFile); !strings.Contains(string(f), "*.ads.example\tCNAME\t.\n") || strings.Contains(string(f), "passthru") {
+		t.Errorf("rules zone after the pause:\n%s", f)
+	}
+	// Reverting a pause resumes blocking.
+	until = env.e.Now().Add(time.Hour)
+	res = env.submit(env.admin, NewRequest(OpBlockingPause, 0, BlockingPauseInput{Until: &until}))
+	rev, err := env.e.Revert(context.Background(), res.ChangesetID, env.admin)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := env.e.Apply(context.Background(), rev.ID, env.admin, ApplyOptions{}); err != nil || env.state().Settings.BlockingPausedUntil != nil {
+		t.Errorf("revert of a pause: %v, %v", err, env.state().Settings.BlockingPausedUntil)
+	}
+	// At most a day.
+	long := env.e.Now().Add(48 * time.Hour)
+	if e := env.submitErr(env.admin, NewRequest(OpBlockingPause, 0, BlockingPauseInput{Until: &long})); e.Kind != KindBadRequest {
+		t.Errorf("a two-day pause: %+v", e)
+	}
+}