fix(cron): serialize lifecycle script reads with SQLite locks

cron/lifecycle_guard.py

@@ -1009,6 +1009,28 @@ def _has_binary_magic(data: bytes) -> bool:
 
 def _read_referenced_script(
     path: Path, *, max_bytes: Optional[int] = None
+) -> tuple[Optional[str], bool]:
+    """Read a referenced script without racing SQLite connection lifecycle.
+
+    The registry check must cover the complete ``open``/``read``/``close``
+    sequence. A separate ``has_live_connection`` check would leave a race in
+    which another thread opens SQLite after the check but before this function
+    closes its descriptor, cancelling that connection's POSIX locks.
+    """
+    from hermes_cli.sqlite_safe_read import LiveConnectionError, offline_file_access
+
+    try:
+        with offline_file_access(path, what="read referenced script"):
+            return _read_referenced_script_unlocked(path, max_bytes=max_bytes)
+    except LiveConnectionError:
+        return None, True
+    except (OSError, ValueError):
+        # Invalid path values, including embedded NULs, are not scripts.
+        return None, False
+
+
+def _read_referenced_script_unlocked(
+    path: Path, *, max_bytes: Optional[int] = None
 ) -> tuple[Optional[str], bool]:
     """Return ``(text, unsafe)`` using bounded, regular-file-only reads.
 

tests/cron/test_lifecycle_guard_live_db.py

@@ -0,0 +1,44 @@
+"""Regression tests for raw lifecycle-guard reads of live SQLite files."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+import cron.lifecycle_guard as lifecycle_guard
+from hermes_cli.sqlite_safe_read import connect_tracked
+
+
+def test_referenced_script_read_refuses_live_sqlite_connection(tmp_path, monkeypatch):
+    db = tmp_path / "state.db"
+    conn = connect_tracked(db)
+    try:
+        def must_not_open(*_args, **_kwargs):
+            raise AssertionError("raw-opened a live SQLite database")
+
+        monkeypatch.setattr(lifecycle_guard.os, "open", must_not_open)
+
+        text, unsafe = lifecycle_guard._read_referenced_script(db)
+
+        assert text is None
+        assert unsafe is True
+    finally:
+        conn.close()
+
+
+def test_referenced_script_read_preserves_normal_script_behavior(tmp_path):
+    script = tmp_path / "script.sh"
+    script.write_text("echo ok\n", encoding="utf-8")
+
+    text, unsafe = lifecycle_guard._read_referenced_script(script)
+
+    assert text == "echo ok\n"
+    assert unsafe is False
+
+
+def test_invalid_referenced_script_path_is_still_tolerated():
+    text, unsafe = lifecycle_guard._read_referenced_script(
+        Path("/tmp/hermes\x00binary")
+    )
+
+    assert text is None
+    assert unsafe is False