fix(regression): bad-restore uses custom-html-bkp-bad + ops.py+test_restore.py

backup-bot-two ignores backupbot.backup.path labels and always backs up
the full volume, making path-based restore-RED infeasible.

New approach: custom-html-bkp-bad has no pre_backup → marker never seeded
→ backup snapshot has no ci-marker.txt. pre_restore writes 'mutated'.
After restore: marker is MISSING or 'mutated' → test_restore_returns_state FAILS.
upgrade=skip (no version tags) is acceptable since passing_tiers_before=[install,backup].

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/custom-html-bkp-bad/test_restore.py

@@ -0,0 +1,25 @@
+"""custom-html-bkp-bad — RESTORE assertion (bad-restore RED canary).
+
+pre_restore seeds 'mutated' to ci-marker.txt. The backup snapshot has no ci-marker.txt
+(never seeded by pre_backup). After restore, the marker is either MISSING or 'mutated' —
+never 'original' — so this assertion FAILS → restore tier RED.
+"""
+
+import os
+import sys
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "..", "runner"))
+from harness import lifecycle  # noqa: E402
+
+MARKER_PATH = "/usr/share/nginx/html/ci-marker.txt"
+
+
+def test_restore_returns_state(live_app):
+    result = lifecycle.exec_in_app(
+        live_app, ["sh", "-c", f"cat {MARKER_PATH} 2>/dev/null || echo MISSING"]
+    ).strip()
+    assert result == "original", (
+        f"restore did not return the pre-mutation (backed-up) state: got {result!r}. "
+        "Expected 'original'. The backup had no marker (not seeded by pre_backup), so "
+        "restore cannot recover it — this is the intended failure for the bad-restore RED canary."
+    )