Add blocking: blocklists and block/allow rules with BIND response policy zones

jarld downloads blocklists (Adblock, hosts or plain domains), checks them
daily and reloads named only when a list changed; your own block and
allow rules take precedence, and the most specific rule wins. Lists and
rules apply per view (default: every view that offers recursion). Web UI
Blocking page with name checks, jarl blocklist and jarl block, the
/blocking API, blocked counts in the statistics. Database schema 6.

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

internal/render/stats.go

@@ -69,8 +69,9 @@ func (h *StatsHooks) statsStatement(user *model.Option) string {
 }
 
 // loggingStatement returns the logging statement with Jarl's channel and
-// the responses category, merged into the user's own if there is one.
-func (h *StatsHooks) loggingStatement(user *model.Option) string {
+// the responses category (and rpz, for blocking's rewrites), merged into
+// the user's own if there is one.
+func (h *StatsHooks) loggingStatement(user *model.Option, rpz bool) string {
 	var st *namedconf.Stmt
 	if user != nil {
 		var err error
@@ -84,15 +85,21 @@ func (h *StatsHooks) loggingStatement(user *model.Option) string {
 	b := st.FirstBlock()
 	// Channels must be defined before the categories that use them.
 	b.Stmts = append([]*namedconf.Stmt{h.logChannel()}, b.Stmts...)
-	merged := false
-	for _, s := range b.Stmts {
-		if s.Keyword() == "category" && strings.EqualFold(s.Arg(0), "responses") && s.FirstBlock() != nil {
-			s.FirstBlock().Stmts = append(s.FirstBlock().Stmts, namedconf.NewStmt(StatsChannelName))
-			merged = true
-		}
+	categories := []string{"responses"}
+	if rpz {
+		categories = append(categories, "rpz")
 	}
-	if !merged {
-		b.Stmts = append(b.Stmts, namedconf.NewStmt("category", "responses", namedconf.NewBlock(namedconf.NewStmt(StatsChannelName))))
+	for _, cat := range categories {
+		merged := false
+		for _, s := range b.Stmts {
+			if s.Keyword() == "category" && strings.EqualFold(s.Arg(0), cat) && s.FirstBlock() != nil {
+				s.FirstBlock().Stmts = append(s.FirstBlock().Stmts, namedconf.NewStmt(StatsChannelName))
+				merged = true
+			}
+		}
+		if !merged {
+			b.Stmts = append(b.Stmts, namedconf.NewStmt("category", cat, namedconf.NewBlock(namedconf.NewStmt(StatsChannelName))))
+		}
 	}
 	prefix := ""
 	if user != nil {