Flatten repo structure: move crawler/ to root, remove vqa/ and immoweb/

The crawler subdirectory was the only active project. Moving it to the
repo root simplifies paths and removes the unnecessary nesting. The
vqa/ and immoweb/ directories were legacy/unused and have been removed.

Updated .drone.yml, .gitignore, .claude/ docs, and skills to reflect
the new flat structure.

tests/unit/test_routing.py

@@ -0,0 +1,67 @@
+"""Unit tests for rec/routing.py."""
+import os
+from unittest.mock import patch, MagicMock
+
+import pytest
+
+from rec.routing import TravelMode, transit_route, ROUTES_API_URL, ROUTES_FIELD_MASK
+from rec.exceptions import RoutingApiError
+
+
+class TestTravelMode:
+    def test_enum_values(self) -> None:
+        assert TravelMode.TRANSIT == "TRANSIT"
+        assert TravelMode.BICYCLE == "BICYCLE"
+        assert TravelMode.WALK == "WALK"
+        assert TravelMode.DRIVE == "DRIVE"
+
+    def test_enum_has_four_members(self) -> None:
+        assert len(TravelMode) == 4
+
+
+class TestTransitRoute:
+    @patch("rec.routing.requests.post")
+    @patch("rec.routing.nextMonday")
+    def test_success_response(self, mock_monday: MagicMock, mock_post: MagicMock) -> None:
+        mock_monday.return_value = MagicMock(
+            strftime=MagicMock(return_value="2024-01-08T09:00:00.000000Z")
+        )
+        expected = {"routes": [{"duration": "600s", "distanceMeters": 5000}]}
+        mock_response = MagicMock()
+        mock_response.status_code = 200
+        mock_response.json.return_value = expected
+        mock_post.return_value = mock_response
+
+        with patch.dict(os.environ, {"ROUTING_API_KEY": "test-key"}):
+            result = transit_route(51.5, -0.1, "London Bridge", TravelMode.TRANSIT)
+
+        assert result == expected
+        mock_post.assert_called_once()
+        call_kwargs = mock_post.call_args
+        assert call_kwargs.kwargs["headers"]["X-Goog-Api-Key"] == "test-key"
+
+    @patch("rec.routing.requests.post")
+    @patch("rec.routing.nextMonday")
+    def test_raises_routing_api_error_on_non_200(self, mock_monday: MagicMock, mock_post: MagicMock) -> None:
+        mock_monday.return_value = MagicMock(
+            strftime=MagicMock(return_value="2024-01-08T09:00:00.000000Z")
+        )
+        error_body = {"error": {"message": "Invalid API key", "status": "PERMISSION_DENIED"}}
+        mock_response = MagicMock()
+        mock_response.status_code = 403
+        mock_response.json.return_value = error_body
+        mock_post.return_value = mock_response
+
+        with patch.dict(os.environ, {"ROUTING_API_KEY": "bad-key"}):
+            with pytest.raises(RoutingApiError) as exc_info:
+                transit_route(51.5, -0.1, "London Bridge", TravelMode.TRANSIT)
+
+        assert exc_info.value.status_code == 403
+        assert exc_info.value.response_body == error_body
+
+    def test_raises_key_error_when_api_key_not_set(self) -> None:
+        env = os.environ.copy()
+        env.pop("ROUTING_API_KEY", None)
+        with patch.dict(os.environ, env, clear=True):
+            with pytest.raises(KeyError):
+                transit_route(51.5, -0.1, "London Bridge", TravelMode.TRANSIT)