Source Copenhagen transit data from Rejseplanen GTFS

- Replace OSM Overpass transit data with the Rejseplanen GTFS feed
  (routes keyed by (agency, short name); styles from modes.yaml)
- Draw one shape per (style, ref, direction), choosing the shape that
  serves the most in-area stops so lines pass the stops we show
- Collapse stops by names (verified unambiguous); prune stops whose
  serving refs have no drawn line within 300 m
- Patch Københavns Havn + Nordhavn into the area polygon so ferry
  routes and sub-harbour metro tunnels survive clipping; 100 m buffer
  closes relation boundary slivers
- Drop OSM download pipeline; keep tiled basemap

copenhagen/config/area.json

@@ -5,5 +5,22 @@
     {"name": "Kobenhavns Kommune", "id": 2192363},
     {"name": "Frederiksberg Kommune", "id": 2186660},
     {"name": "Amager", "id": 5175924}
+  ],
+  "waterways": [
+    {
+      "name": "Kobenhavns Havn + Nordhavn",
+      "comment": "The harbour channel and Nordhavn basin belong to the City Pass zone in any practical sense: the metro tunnels under it (M1/M2/M4), harbour ferries 991/992 sail it, and the fade-out should not start mid-harbour. The kommune boundary relations exclude all water, so this polygon is patched in.",
+      "ring": [
+        [12.532, 55.640],
+        [12.545, 55.666],
+        [12.565, 55.680],
+        [12.585, 55.715],
+        [12.612, 55.717],
+        [12.632, 55.685],
+        [12.632, 55.660],
+        [12.600, 55.636],
+        [12.560, 55.634]
+      ]
+    }
   ]
 }