feat(2): bluesky-pds P4 data-integrity overlay — deterministic atproto account marker (recipe-aware; catches running-app-holds-sqlite restore gap) via _p4.py + ops/test_upgrade/backup/restore

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/bluesky-pds/ops.py

@@ -0,0 +1,22 @@
+"""bluesky-pds — pre-op seed hooks (Phase 1e HC3). The P4 marker is a deterministic atproto account
+(recipe-aware data in the PDS sqlite under /pds, the backed-up volume) — see _p4.py. pre_restore
+deletes the account so a successful restore is observable (non-vacuous)."""
+
+import os
+import sys
+
+sys.path.insert(0, os.path.dirname(__file__))
+import _p4  # noqa: E402
+
+
+def pre_upgrade(domain, meta):
+    _p4.create_account(domain)
+
+
+def pre_backup(domain, meta):
+    _p4.create_account(domain)
+
+
+def pre_restore(domain, meta):
+    _p4.delete_account(domain)
+    assert not _p4.account_exists(domain), "marker account delete did not take (pre_restore)"