Refactor UI assets and harden quality checks

tests/test_rfc2136.py

@@ -0,0 +1,25 @@
+from karldns.dns.rfc2136 import _apply_record_update, _RecordUpdate
+
+
+class _FakeUpdate:
+    def __init__(self) -> None:
+        self.calls: list[tuple[object, ...]] = []
+
+    def replace(self, *args: object) -> None:
+        self.calls.append(("replace", *args))
+
+    def delete(self, *args: object) -> None:
+        self.calls.append(("delete", *args))
+
+
+def test_apply_record_update_replaces_deletes_or_skips_record_type() -> None:
+    update = _FakeUpdate()
+
+    _apply_record_update(update, "home", _RecordUpdate(ttl=60, record_type="A", value="203.0.113.7", enabled=True))
+    _apply_record_update(update, "home", _RecordUpdate(ttl=60, record_type="AAAA", value=None, enabled=True))
+    _apply_record_update(update, "home", _RecordUpdate(ttl=60, record_type="TXT", value="ignored", enabled=False))
+
+    assert update.calls == [
+        ("replace", "home", 60, "A", "203.0.113.7"),
+        ("delete", "home", "AAAA"),
+    ]