fix: convert feed timestamps to US/Eastern and add test

Made-with: Cursor

tests/test_fetcher.py

@@ -81,3 +81,19 @@ def test_fetch_handles_feed_error(app, db):
 
         assert result["error"] is not None
         assert Article.query.count() == 0
+
+
+def test_fetch_converts_timezone_to_eastern(app, db):
+    with app.app_context():
+        with patch("src.fetcher.requests.get") as mock_get:
+            mock_get.return_value = _mock_feed_response(SAMPLE_RSS_XML)
+            with patch("src.fetcher.process_image") as mock_img:
+                mock_img.return_value = ("/fake/path.jpg", 800, 450)
+                fetch_and_cache_articles()
+
+        article = Article.query.filter_by(title="Test Article One").first()
+        # The XML has: Mon, 06 Apr 2026 12:00:00 +0000
+        # US/Eastern in April is EDT (UTC-4), so it should be 08:00:00
+        assert article.pub_date.tzinfo is None
+        assert article.pub_date.hour == 8
+        assert article.pub_date.minute == 0