Add disney_group grouped park filter categories

- New disney_group query param on /api/assets (park, resort,
  office, springs, other)
- Both list and map filter dropdowns show group options above
  individual parks
- Backend uses IN queries for grouped park values
- Map view handles groups via client-side PARK_GROUP_MAP

Closes #69

server.py

@@ -1065,6 +1065,7 @@ def list_assets(
     assigned_to: Optional[int] = Query(None),
     disney_park: Optional[str] = Query(None),
     disney_filter: Optional[str] = Query(None),
+    disney_group: Optional[str] = Query(None, description="Grouped park categories: park, resort, office, springs, other"),
     q: Optional[str] = Query(None),
     no_dex_days: Optional[int] = Query(None, ge=1),
     has_gps: Optional[bool] = Query(None),
@@ -1092,6 +1093,19 @@ def list_assets(
         conditions.append("is_disney = 1")
     elif disney_filter == "non_disney":
         conditions.append("(is_disney IS NULL OR is_disney = 0)")
+    if disney_group:
+        park_groups = {
+            "park": ["magic-kingdom", "epcot", "hollywood-studios", "animal-kingdom"],
+            "resort": ["resort"],
+            "office": ["office"],
+            "springs": ["disney-springs"],
+            "other": ["other"],
+        }
+        parks = park_groups.get(disney_group)
+        if parks:
+            placeholders = ",".join("?" * len(parks))
+            conditions.append(f"disney_park IN ({placeholders})")
+            params.extend(parks)
     if model:
         conditions.append("model = ?")
         params.append(model)