feat: add conversation_type and briefing_date to Conversation model

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/test_briefing_models.py

@@ -0,0 +1,20 @@
+def test_conversation_has_briefing_fields():
+    """Conversation model must declare conversation_type and briefing_date."""
+    from fabledassistant.models.conversation import Conversation
+    cols = {c.key for c in Conversation.__table__.columns}
+    assert "conversation_type" in cols
+    assert "briefing_date" in cols
+
+
+def test_rss_models_exist():
+    from fabledassistant.models.rss_feed import RssFeed, RssItem
+    feed_cols = {c.key for c in RssFeed.__table__.columns}
+    item_cols = {c.key for c in RssItem.__table__.columns}
+    assert {"id", "user_id", "url", "title", "last_fetched_at"} <= feed_cols
+    assert {"id", "feed_id", "guid", "title", "url", "published_at", "content"} <= item_cols
+
+
+def test_weather_cache_model_exists():
+    from fabledassistant.models.weather_cache import WeatherCache
+    cols = {c.key for c in WeatherCache.__table__.columns}
+    assert {"id", "user_id", "location_key", "location_label", "forecast_json", "previous_json", "fetched_at"} <= cols