feat(mailu): add ops.py + backup/restore tests + update PARITY.md (P4 now covered via PR#3)

tests/mailu/ops.py

@@ -0,0 +1,36 @@
+"""mailu — pre-op seed hooks. Creates / deletes a test mailbox in the admin sqlite DB to prove
+backup→restore data integrity on real mail data (P4 coverage, phase-mailu)."""
+
+from __future__ import annotations
+
+import os
+import sys
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "..", "runner"))
+from harness import lifecycle  # noqa: E402
+
+sys.path.insert(0, os.path.dirname(__file__))
+import _mailu  # noqa: E402
+
+_CI_LOCALPART = "citest"
+_CI_PASSWORD = "CcCi-BackupTest1!Aa"
+
+
+def pre_backup(ctx):
+    _mailu.ensure_domain(ctx.domain, ctx.domain)
+    _mailu.create_user(ctx.domain, _CI_LOCALPART, ctx.domain, _CI_PASSWORD)
+
+
+def pre_restore(ctx):
+    # Delete the seeded user directly from sqlite to simulate data loss before restore.
+    # (flask mailu has no user-delete subcommand in 2024.06.52; sqlite3 module is always available.)
+    lifecycle.exec_in_app(
+        ctx.domain,
+        [
+            "python3",
+            "-c",
+            f"import sqlite3; db=sqlite3.connect('/data/main.db'); "
+            f"db.execute(\"DELETE FROM user WHERE localpart='{_CI_LOCALPART}'\"); db.commit()",
+        ],
+        service="admin",
+    )