Add train and ferry support to location tracking

- Add helper functions for train and ferry location extraction
- Update get_location_for_date to consider trains and ferries alongside flights
- Parse stations.yaml and ferry_terminals.yaml for location data
- Handle UK vs international locations consistently for all transport modes
- Add comprehensive tests for new train and ferry location helpers
- Format code with black for consistent style

Now tracks complete travel history including flights, trains, ferries, and accommodation for accurate location determination.

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

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

tests/test_busy.py

@@ -178,6 +178,68 @@ def test_parse_datetime_field():
     assert parsed_dt.day == 1
 
 
+def test_train_location_helpers():
+    """Test the train location helper functions."""
+    from agenda.busy import _get_train_location
+
+    # Mock station data
+    stations = [
+        {"name": "London St Pancras", "country": "gb"},
+        {"name": "Brussels Midi", "country": "be"},
+        {"name": "Edinburgh Waverley", "country": "gb"},
+    ]
+
+    # Test UK station when not on trip (should return None for home)
+    train_leg = {"to": "London St Pancras"}
+    location = _get_train_location(train_leg, stations, on_trip=False)
+    assert location[0] is None  # Should be home
+    assert location[1].alpha_2 == "GB"
+
+    # Test UK station when on trip (should return city name)
+    location = _get_train_location(train_leg, stations, on_trip=True)
+    assert location[0] == "London St Pancras"
+    assert location[1].alpha_2 == "GB"
+
+    # Test non-UK station
+    train_leg = {"to": "Brussels Midi"}
+    location = _get_train_location(train_leg, stations, on_trip=False)
+    assert location[0] == "Brussels Midi"
+    assert location[1].alpha_2 == "BE"
+
+
+def test_ferry_location_helpers():
+    """Test the ferry location helper functions."""
+    from agenda.busy import _get_ferry_location
+
+    # Mock terminal data
+    terminals = [
+        {"name": "Dover Eastern Docks", "country": "gb", "city": "Dover"},
+        {"name": "Calais Ferry Terminal", "country": "fr", "city": "Calais"},
+        {
+            "name": "Portsmouth Continental Terminal",
+            "country": "gb",
+            "city": "Portsmouth",
+        },
+    ]
+
+    # Test UK terminal when not on trip (should return None for home)
+    ferry = {"to": "Dover Eastern Docks"}
+    location = _get_ferry_location(ferry, terminals, on_trip=False)
+    assert location[0] is None  # Should be home
+    assert location[1].alpha_2 == "GB"
+
+    # Test UK terminal when on trip (should return city name)
+    location = _get_ferry_location(ferry, terminals, on_trip=True)
+    assert location[0] == "Dover"
+    assert location[1].alpha_2 == "GB"
+
+    # Test non-UK terminal
+    ferry = {"to": "Calais Ferry Terminal"}
+    location = _get_ferry_location(ferry, terminals, on_trip=False)
+    assert location[0] == "Calais"
+    assert location[1].alpha_2 == "FR"
+
+
 def test_get_busy_events(app_context, trips):
     """Test get_busy_events function."""
     start_date = date(2023, 1, 1)