fix: Update search service test to use timezone-aware datetime comparison

The test_after_date test was comparing timezone-naive datetime(2020, 1, 1)
with timezone-aware search results, causing a TypeError.

Fixed by making both past_date and future_date timezone-aware using
.astimezone() for consistent comparison with search result timestamps.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>
Signed-off-by: Joe P <joe@basicmemory.com>

Author: jope-bm

tests/services/test_search_service.py

@@ -155,7 +155,7 @@ async def test_after_date(search_service, test_graph):
     """Test search filters."""
 
     # Should find with past date
-    past_date = datetime(2020, 1, 1)
+    past_date = datetime(2020, 1, 1).astimezone()
     results = await search_service.search(
         SearchQuery(
             text="entity",
@@ -166,7 +166,7 @@ async def test_after_date(search_service, test_graph):
         assert datetime.fromisoformat(r.created_at) > past_date
 
     # Should not find with future date
-    future_date = datetime(2030, 1, 1)
+    future_date = datetime(2030, 1, 1).astimezone()
     results = await search_service.search(
         SearchQuery(
             text="entity",