feat(workshop): make brand/model required, plate optional, remove VIN

- create_vehicle endpoints now require make and model; plate is optional; VIN is no longer stored.

- Updated new-vehicle modal: removed VIN field, plate is optional, brand/model marked required.

pos/blueprints/fleet_bp.py

@@ -269,11 +269,12 @@ def list_all_history():
 def create_vehicle():
     """Create a fleet vehicle.
 
-    Body: {customer_id, plate, vin, make, model, year, current_mileage, fuel_type, color, owner_name, notes}
+    Body: {customer_id, plate, make, model, year, current_mileage, fuel_type, color, owner_name, notes}
+    Brand and model are required; plate is optional; VIN is not used.
     """
     data = request.get_json() or {}
-    if not data.get('plate') and not data.get('vin'):
-        return jsonify({'error': 'plate or vin is required'}), 400
+    if not data.get('make') or not data.get('model'):
+        return jsonify({'error': 'Marca y modelo son obligatorios'}), 400
     if not data.get('customer_id'):
         return jsonify({'error': 'El vehiculo debe estar asignado a un cliente'}), 400
 
@@ -291,12 +292,12 @@ def create_vehicle():
 
         cur.execute("""
             INSERT INTO fleet_vehicles
-                (branch_id, customer_id, plate, vin, make, model, year,
+                (branch_id, customer_id, plate, make, model, year,
                  current_mileage, fuel_type, color, owner_name, notes)
-            VALUES (%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)
+            VALUES (%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)
             RETURNING id
         """, (
-            branch_id, data['customer_id'], data.get('plate'), data.get('vin'),
+            branch_id, data['customer_id'], data.get('plate'),
             data.get('make'), data.get('model'), data.get('year'),
             data.get('current_mileage', 0), data.get('fuel_type', 'gasolina'),
             data.get('color'), data.get('owner_name') or cust[0], data.get('notes'),