style: apply black formatting across codebase 🎨

No logic changes — pure reformatting of line lengths, dict literals,
method-chain line breaks, and trailing newlines to satisfy black's style.

tests/test_coredns_mysql.py

@@ -1,4 +1,5 @@
 """Tests for the CoreDNS MySQL backend (run against in-memory SQLite)."""
+
 import pytest
 from sqlalchemy import create_engine
 from sqlalchemy.orm import scoped_session, sessionmaker
@@ -141,8 +142,16 @@ def test_reconcile_removes_extra_records(mysql_backend):
     # Inject a phantom record directly into the DB
     session = mysql_backend.Session()
     zone = session.query(Zone).filter_by(zone_name="example.com.").first()
-    session.add(Record(zone_id=zone.id, hostname="phantom", type="A",
-                       data="10.0.0.99", ttl=300, online=True))
+    session.add(
+        Record(
+            zone_id=zone.id,
+            hostname="phantom",
+            type="A",
+            data="10.0.0.99",
+            ttl=300,
+            online=True,
+        )
+    )
     session.commit()
     session.close()