feat: add is_disney column for reliable Disney/Non-Disney filtering

- Added is_disney INTEGER DEFAULT 0 column to assets table
- Backfilled 996 Disney assets based on D- customer prefix
- Server: is_disney in AssetCreate/AssetUpdate models, INSERT/UPDATE
- Server: disney_filter query param now uses is_disney column (no JOIN needed)
- import_cantaloupe.py: sets is_disney=1 when customer starts with D-
- import_machines.py: sets is_disney=1 when customer starts with D-
- disney_classify.py: sets is_disney=1 when classifying
- Frontend: new Location Type dropdown with Disney/Non-Disney toggle
  (replaces the __disney__/__non_disney__ park dropdown pseudo-options)

import_cantaloupe.py

@@ -141,17 +141,18 @@ def import_assets():
         # Customer lookup
         customer_id = customer_map.get(customer_name)
         
+        is_disney = 1 if customer_name.startswith('D-') else 0
         try:
             cursor = conn.execute("""
                 INSERT INTO assets 
                     (machine_id, name, description, category, status, 
                      make, model, serial_number, address, room, 
-                     customer_id)
-                VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+                     customer_id, is_disney)
+                VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
             """, (
                 machine_id, name, description, "Equipment", status,
                 make, model, serial, full_address, place,
-                customer_id,
+                customer_id, is_disney,
             ))
             inserted += 1
         except sqlite3.IntegrityError as e: