希望subNVue.hide也能有一个callback

**新功能描述**
希望subNVue.hide能像subNVue.show一样有个完成之后的callback

**现状及问题**
我需要隐藏subnvue来展示一个遮罩层，但是由于subNVue.hide没有callback导致在低端机上面会出现subnvue还没有完全隐藏我遮罩出现的情况，这时候遮罩盖不住subnuve导致有留白的区域

**尝试方案**
[如果你有尝试绕开或其它解决方案，在这里描述你的建议方案]

**补充信息**
[其它你认为有参考价值的信息]

Start by locating the subNVue.hide and subNVue.show entry points and compare how show reports completion. Trace the hide transition far enough to identify when the subNVue is fully hidden, then verify that the callback runs at that point, including on lower-end devices; done means callers can safely show an overlay without visible gaps.

Written by the indexing model from the issue text.