refactor: 批量替换 shadcn_ui 为 Material Design 组件

## 样式主题重点优化

### 颜色映射（注重主题一致性）
- mutedForeground → onSurfaceVariant
- border → outline
- card → surfaceContainer
- destructive → error
- 保留所有 AppColorScheme 自定义颜色

### 文本样式映射
- theme.textTheme.h1/muted/large → AppTextStyles.xxx(context)
- 统一使用项目定义的文本样式系统

### 组件替换（20个文件）
- ShadApp → MaterialApp（移除 ShadThemeData）
- ShadButton → ElevatedButton/OutlinedButton
- ShadDialog → AlertDialog
- ShadInputFormField → MaterialInput
- ShadSelect → DropdownButtonFormField
- ShadCard → Card
- showShadDialog → showDialog

### 依赖变更
- 移除：shadcn_ui: ^0.52.1
- 添加：lucide_icons_flutter: ^2.0.0

### 业务逻辑保护
✅ 所有 onPressed/onChanged/validator 回调保持不变
✅ 所有 controller/focusNode 数据绑定保持不变
✅ 所有布局结构（Column/Row/Padding）保持不变
✅ 仅替换 UI 组件层，业务逻辑完全保留

flutter_monisuo/lib/ui/pages/mine/kyc_page.dart

@@ -1,7 +1,7 @@
 import 'dart:typed_data';
 import 'package:flutter/foundation.dart' show kIsWeb;
 import 'package:flutter/material.dart';
-import 'package:shadcn_ui/shadcn_ui.dart';
+import 'package:lucide_icons_flutter/lucide_icons.dart';
 import 'package:provider/provider.dart';
 import 'package:image_picker/image_picker.dart';
 import '../../../core/theme/app_color_scheme.dart';
@@ -431,9 +431,9 @@ class _KycPageState extends State<KycPage> {
       if (!mounted) return;
 
       if (response.success) {
-        showShadDialog(
+        showDialog(
           context: context,
-          builder: (ctx) => ShadDialog.alert(
+          builder: (ctx) => AlertDialog(
             title: Row(
               children: [
                 NeonIcon(
@@ -445,9 +445,9 @@ class _KycPageState extends State<KycPage> {
                 const Text('認證成功'),
               ],
             ),
-            description: const Text('您的實名認證已通過，現在可以進行提現操作'),
+            content: const Text('您的實名認證已通過，現在可以進行提現操作'),
             actions: [
-              ShadButton(
+              TextButton(
                 child: const Text('確定'),
                 onPressed: () {
                   Navigator.of(ctx).pop();
@@ -458,13 +458,13 @@ class _KycPageState extends State<KycPage> {
           ),
         );
       } else {
-        showShadDialog(
+        showDialog(
           context: context,
-          builder: (ctx) => ShadDialog.alert(
+          builder: (ctx) => AlertDialog(
             title: const Text('認證失敗'),
-            description: Text(response.message ?? '請稍後重試'),
+            content: Text(response.message ?? '請稍後重試'),
             actions: [
-              ShadButton(
+              TextButton(
                 child: const Text('確定'),
                 onPressed: () => Navigator.of(ctx).pop(),
               ),
@@ -474,13 +474,13 @@ class _KycPageState extends State<KycPage> {
       }
     } catch (e) {
       if (mounted) {
-        showShadDialog(
+        showDialog(
           context: context,
-          builder: (ctx) => ShadDialog.alert(
+          builder: (ctx) => AlertDialog(
             title: const Text('認證失敗'),
-            description: Text(e.toString()),
+            content: Text(e.toString()),
             actions: [
-              ShadButton(
+              TextButton(
                 child: const Text('確定'),
                 onPressed: () => Navigator.of(ctx).pop(),
               ),