feat(customers): show vehicles and delete customer

- get_customer now returns fleet_vehicles assigned to the customer.

- Added DELETE /pos/api/customers/<id> soft-delete (is_active=false) with customers.delete permission.

- Added Vehicles section in customer detail panel.

- Added Eliminar button in quick actions (owner/admin/customers.delete).

pos/blueprints/customers_bp.py

@@ -165,6 +165,21 @@ def get_customer(customer_id):
         float(customer['credit_limit']) - float(customer['credit_balance']), 2
     )
 
+    # Fleet vehicles assigned to this customer
+    cur.execute("""
+        SELECT id, plate, vin, make, model, year, current_mileage, color, owner_name, is_active, created_at
+        FROM fleet_vehicles
+        WHERE customer_id = %s
+        ORDER BY is_active DESC, created_at DESC
+    """, (customer_id,))
+    customer['fleet_vehicles'] = []
+    for r in cur.fetchall():
+        customer['fleet_vehicles'].append({
+            'id': r[0], 'plate': r[1], 'vin': r[2], 'make': r[3], 'model': r[4],
+            'year': r[5], 'current_mileage': r[6], 'color': r[7], 'owner_name': r[8],
+            'is_active': r[9], 'created_at': str(r[10]) if r[10] else None,
+        })
+
     cur.close()
     conn.close()
     return jsonify(customer)
@@ -303,6 +318,26 @@ def update_customer(customer_id):
     return jsonify({'message': 'Customer updated'})
 
 
+@customers_bp.route('/<int:customer_id>', methods=['DELETE'])
+@require_auth('customers.delete')
+def delete_customer(customer_id):
+    """Soft-delete (deactivate) a customer."""
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+
+    cur.execute("SELECT id FROM customers WHERE id = %s", (customer_id,))
+    if not cur.fetchone():
+        cur.close(); conn.close()
+        return jsonify({'error': 'Customer not found'}), 404
+
+    cur.execute("UPDATE customers SET is_active = false WHERE id = %s", (customer_id,))
+    log_action(conn, 'CUSTOMER_DEACTIVATE', 'customer', customer_id)
+    conn.commit()
+    cur.close()
+    conn.close()
+    return jsonify({'message': 'Cliente eliminado'})
+
+
 @customers_bp.route('/<int:customer_id>/statement', methods=['GET'])
 @require_auth('customers.view')
 def customer_statement(customer_id):