Explore: several values per filter, !value to leave one out, *.domain

Each explore filter takes several values, comma separated (any of them), !value to leave one out, and *.example.com for a name and the names below it. Every value is a chip with its own ✕; clicking a value in the lists adds it, and hide leaves it out. The filter bar's fields take lists. domain= still works.

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

internal/stats/explore_test.go

@@ -84,6 +84,39 @@ func TestExplore(t *testing.T) {
 		t.Errorf("internal NXDOMAIN: %d", ex.Total)
 	}
 
+	// Several values: any of them; !values: none of them.
+	total := func(f ExploreFilter) int64 {
+		t.Helper()
+		ex, err := q.Explore(ctx, f, 10, 50)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return ex.Total
+	}
+	for _, c := range []struct {
+		f    ExploreFilter
+		want int64
+	}{
+		{ExploreFilter{Client: "10.0.0.5, 198.51.100.7"}, 6},
+		{ExploreFilter{Client: "!10.0.0.5"}, 2},
+		{ExploreFilter{RCode: "NXDOMAIN,noerror"}, 6},
+		{ExploreFilter{Name: "*.adbraun.lol"}, 5},
+		{ExploreFilter{Name: "!*.adbraun.lol"}, 1},
+		{ExploreFilter{Name: "www.adbraun.lol,nas.adbraun.lol"}, 2},
+		{ExploreFilter{Name: "*.adbraun.lol, !typo.adbraun.lol", Client: "!198.51.100.7"}, 2},
+		{ExploreFilter{Blocked: "!hagezi"}, 5},
+		{ExploreFilter{Domain: "adbraun.lol", Name: "!nope.adbraun.lol"}, 3},
+	} {
+		if got := total(c.f); got != c.want {
+			t.Errorf("%+v: %d answers, want %d", c.f, got, c.want)
+		}
+	}
+	// Two clients: their breakdown shows them side by side.
+	ex, _ = q.Explore(ctx, ExploreFilter{Client: "10.0.0.5,198.51.100.7"}, 10, 50)
+	if len(ex.By["client"]) != 2 {
+		t.Errorf("two clients' breakdown %+v", ex.By["client"])
+	}
+
 	// Pruning: past the retention they go.
 	clk.t = clk.t.Add(8 * 24 * time.Hour)
 	c.prune(ctx)