完善下单逻辑及其ui展示，修复支付倒计时显示错误bug

mall_sql/migrations/20260525_consumer_order_soft_delete.sql

@@ -0,0 +1,17 @@
+BEGIN;
+
+ALTER TABLE public.ml_orders
+    ADD COLUMN IF NOT EXISTS cancelled_at TIMESTAMPTZ NULL,
+    ADD COLUMN IF NOT EXISTS consumer_deleted_at TIMESTAMPTZ NULL;
+
+COMMENT ON COLUMN public.ml_orders.cancelled_at IS '订单取消时间，包含用户取消与支付超时取消';
+COMMENT ON COLUMN public.ml_orders.consumer_deleted_at IS '消费者侧软删除时间，仅影响消费者订单列表展示';
+
+CREATE INDEX IF NOT EXISTS idx_ml_orders_consumer_deleted_at
+ON public.ml_orders(user_id, consumer_deleted_at, created_at DESC);
+
+CREATE INDEX IF NOT EXISTS idx_ml_orders_consumer_visible
+ON public.ml_orders(user_id, created_at DESC)
+WHERE consumer_deleted_at IS NULL;
+
+COMMIT;