Remove artificial Starter route, use real PokeDB starter locations

Replace the synthetic "Starter" route with actual in-game locations
(e.g. Professor Oak's Laboratory, Iki Town, Littleroot Town). Starters
now appear at their real locations with method "starter" by remapping
PokeDB's "gift" method during import. Split ruby-sapphire and
black-2-white-2 out of special_encounters aliases since their starter
locations differ from the aliased version groups.

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

tools/import-pokedb/import_pokedb/output.py

@@ -140,7 +140,20 @@ def merge_special_encounters(
             ))
 
         if location_name in route_map:
-            route_map[location_name].encounters.extend(encounters)
+            existing = route_map[location_name].encounters
+            for enc in encounters:
+                # If a starter encounter matches an existing gift encounter,
+                # update the method to "starter" instead of adding a duplicate.
+                if enc.method == "starter":
+                    match = next(
+                        (e for e in existing
+                         if e.pokeapi_id == enc.pokeapi_id and e.method == "gift"),
+                        None,
+                    )
+                    if match:
+                        match.method = "starter"
+                        continue
+                existing.append(enc)
         else:
             new_route = Route(name=location_name, order=0, encounters=encounters)
             routes.append(new_route)