fix(monitoring): restore Cloud messages and bot-scoped sessions (#2526)

* fix(monitoring): restore Cloud message persistence and bot-scoped sessions

* fix(migrations): support partial monitoring schemas and align regression fixtures

* test(migrations): complete raw bot session fixture values

---------

Co-authored-by: dadachann <185672915+dadachann@users.noreply.github.com>

tests/unit_tests/api/service/test_monitoring_identifiers.py

@@ -0,0 +1,19 @@
+"""Identifier normalization must not rely on SQLite's permissive codecs."""
+
+import pytest
+
+from langbot.pkg.api.http.service import monitoring
+
+
+@pytest.mark.parametrize(
+    ('value', 'expected'),
+    [(None, None), ('', ''), ('00123', '00123'), ('  用户  ', '  用户  '), (123, '123'), (-123, '-123'), (0, '0')],
+)
+def test_normalize_user_id_preserves_opaque_strings(value, expected):
+    assert monitoring._normalize_user_id(value) == expected
+
+
+@pytest.mark.parametrize('value', [True, False, 1.5, b'123', ['123'], {'id': 123}])
+def test_normalize_user_id_rejects_unsupported_types(value):
+    with pytest.raises(TypeError, match='user_id must be a string, integer, or None'):
+        monitoring._normalize_user_id(value)