checker: split monolithic rule into per-concern rules

checker/rules_delegation.go

@@ -0,0 +1,13 @@
+package checker
+
+import sdk "git.happydns.org/checker-sdk-go/checker"
+
+// delegationRule covers Zonemaster's delegation test module (parent/child NS
+// agreement, glue correctness, referral integrity).
+func delegationRule() sdk.CheckRule {
+	return &categoryRule{
+		name:        "zonemaster.delegation",
+		description: "Zonemaster delegation tests (parent/child NS agreement, glue, referrals).",
+		modules:     []string{"delegation"},
+	}
+}