fix(security): harden Python service boundaries

tests/test_notes_reminder_temporal_redos.py

@@ -0,0 +1,60 @@
+"""manage_notes reminder-time sniffing must stay linear (CodeQL py/polynomial-redos).
+
+`\\d{1,2}(?::\\d{2})?\\s*(?:am|pm)?\\s+today` let `\\s*` and `\\s+` split one
+whitespace run every possible way, so a digit followed by a long whitespace
+run in model-supplied note text was O(n^2). The rewrite groups the optional
+meridiem with its own whitespace: same language, one way to match.
+"""
+
+import json
+import sys
+import time
+import uuid
+
+import pytest
+
+from tests.helpers.import_state import clear_fake_database_modules
+from tests.helpers.sqlite_db import make_temp_sqlite
+
+clear_fake_database_modules()
+
+import core.database as cdb
+
+_TS, _ENGINE, _TMPDB = make_temp_sqlite(cdb.Base.metadata)
+
+
+@pytest.fixture(autouse=True)
+def _bind_temp_db(monkeypatch):
+    monkeypatch.setitem(sys.modules, "core.database", cdb)
+    parent = sys.modules.get("core")
+    if parent is not None:
+        monkeypatch.setattr(parent, "database", cdb, raising=False)
+    monkeypatch.setattr(cdb, "SessionLocal", _TS)
+    yield
+
+
+async def _add(content):
+    from src.tool_implementations import do_manage_notes
+
+    return await do_manage_notes(
+        json.dumps({"action": "add", "title": "remind me", "content": content}),
+        owner="tester-" + uuid.uuid4().hex[:6],
+    )
+
+
+async def test_reminder_time_sniffing_whitespace_flood_is_linear():
+    started = time.perf_counter()
+    res = await _add("remind 1" + "\t" * 40_000 + "x")
+    assert time.perf_counter() - started < 2.0
+    assert res.get("exit_code", 0) == 0, res
+
+
+async def test_reminder_time_sniffing_still_finds_time_first_phrases():
+    res = await _add("remind me to call mom, 9 pm tomorrow")
+    assert res.get("exit_code", 0) == 0, res
+    db = _TS()
+    try:
+        note = db.query(cdb.Note).filter(cdb.Note.id == res["note_id"]).first()
+        assert note is not None and "T21:00:00" in (note.due_date or ""), note and note.due_date
+    finally:
+        db.close()