fix: 修复划转页面卡片互换动画效果

- 重写 AnimatedSwitcher 实现，移除多余的 Container 包裹
- 直接在 _buildAccountCard 上设置 ValueKey
- 使用 SlideTransition + FadeTransition 组合
- 上方卡片从上滑入，下方卡片从下滑入
- 动画时长 300ms，easeInOut 曲线
- 动画效果更流畅自然，卡片互换位置清晰可见

flutter_monisuo/build/web/main.dart.js_100.part.js

@@ -1,15 +1,15 @@
 ((a,b)=>{a[b]=a[b]||{}})(self,"$__dart_deferred_initializers__")
 $__dart_deferred_initializers__.current=function(a,b,c,$){var B,A={
-b4H(d,e,f){var y,x,w=null,v=new B.a0(),u=new B.a0()
-u=new A.ZA(v,u)
+b4L(d,e,f){var y,x,w=null,v=new B.a0(),u=new B.a0()
+u=new A.ZD(v,u)
 u.bf(d,w,e,w)
 y=u.a
 x=v.r
 x.toString
 y.r=x
-v.r=A.bnC(u)
+v.r=A.bnG(u)
 return u},
-bmi(d,e){var y
+bmm(d,e){var y
 A:{if("timePicker.hours"===e){y="Masaa"
 break A}if("timePicker.minutes"===e){y="Dakika"
 break A}if("timePicker.seconds"===e){y="Sekunde"
@@ -23,38 +23,38 @@ break A}if("input.selectAll"===e){y="Chagua yote"
 break A}if("keyboardToolbar.done"===e){y="Imekamilika"
 break A}y=null
 break A}return y},
-bnC(d){return new A.aSu(d)},
-ZA:function ZA(d,e){var _=this
+bnG(d){return new A.aSy(d)},
+ZD:function ZD(d,e){var _=this
 _.r=d
 _.z=_.w=$
 _.a=e
 _.e=_.b=$},
-aOX:function aOX(){},
-aSu:function aSu(d){this.a=d},
-aaB:function aaB(){}}
+aOZ:function aOZ(){},
+aSy:function aSy(d){this.a=d},
+aaD:function aaD(){}}
 B=c[0]
 A=a.updateHolder(c[71],A)
-A.ZA.prototype={
+A.ZD.prototype={
 h(d,e){var y=this.r.a4(e)
 return y==null?this.a.a4(e):y},
 gb4(){var y=this,x=y.z
 if(x===$){if(y.w===$)y.w=y
-x=y.z=new A.aOX()}return x},
+x=y.z=new A.aOZ()}return x},
 gb9(){return this.r}}
-A.aOX.prototype={
+A.aOZ.prototype={
 gbh(){return"Kata"},
 gbg(){return"Nakili"},
 gbi(){return"Bandika"},
 gbe(){return"Chagua yote"}}
-A.aaB.prototype={}
+A.aaD.prototype={}
 var z=a.updateTypes([])
-A.aSu.prototype={
-$1(d){return A.bmi(this.a,d)},
+A.aSy.prototype={
+$1(d){return A.bmm(this.a,d)},
 $S:2};(function inheritance(){var y=a.mixin,x=a.inherit
-x(A.aaB,B.a_)
-x(A.ZA,A.aaB)
-x(A.aOX,B.aZ)
-x(A.aSu,B.aR)
-y(A.aaB,B.aX)})()
-B.b4(b.typeUniverse,JSON.parse('{"ZA":{"a_":[]}}'))};
-(a=>{a["w0IWjnBfFrvddsCJ2K+ikw9RFGc="]=a.current})($__dart_deferred_initializers__);
+x(A.aaD,B.a_)
+x(A.ZD,A.aaD)
+x(A.aOZ,B.aZ)
+x(A.aSy,B.aR)
+y(A.aaD,B.aX)})()
+B.b3(b.typeUniverse,JSON.parse('{"ZD":{"a_":[]}}'))};
+(a=>{a["LF1I63rLW8EpIqkNzxrMJNlEndA="]=a.current})($__dart_deferred_initializers__);