refactor(apps): 主题系统迁移至 ColorScheme + 扩展架构并支持 Dark Mode

apps/lib/features/home/presentation/screens/home_sheet.dart

@@ -2,7 +2,6 @@ import 'package:flutter/material.dart';
 import 'package:image_picker/image_picker.dart';
 import 'package:lucide_icons/lucide_icons.dart';
 import '../../../../core/l10n/l10n.dart';
-import '../../../../core/theme/design_tokens.dart';
 
 class HomeSheet extends StatelessWidget {
   final Function(List<XFile>) onImagesSelected;
@@ -11,10 +10,12 @@ class HomeSheet extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final colorScheme = Theme.of(context).colorScheme;
+
     return GestureDetector(
       onTap: () => Navigator.of(context).pop(),
       child: Container(
-        color: const Color(0x4D0F172A),
+        color: colorScheme.scrim.withValues(alpha: 0.3),
         child: Column(
           mainAxisAlignment: MainAxisAlignment.end,
           children: [
@@ -23,9 +24,11 @@ class HomeSheet extends StatelessWidget {
               child: Container(
                 width: double.infinity,
                 padding: const EdgeInsets.all(16),
-                decoration: const BoxDecoration(
-                  color: AppColors.white,
-                  borderRadius: BorderRadius.vertical(top: Radius.circular(28)),
+                decoration: BoxDecoration(
+                  color: colorScheme.surface,
+                  borderRadius: const BorderRadius.vertical(
+                    top: Radius.circular(28),
+                  ),
                 ),
                 child: Column(
                   children: [
@@ -33,7 +36,7 @@ class HomeSheet extends StatelessWidget {
                       width: 36,
                       height: 4,
                       decoration: BoxDecoration(
-                        color: AppColors.slate300,
+                        color: colorScheme.outlineVariant,
                         borderRadius: BorderRadius.circular(2),
                       ),
                     ),
@@ -79,6 +82,8 @@ class HomeSheet extends StatelessWidget {
     required String label,
     required VoidCallback onTap,
   }) {
+    final colorScheme = Theme.of(context).colorScheme;
+
     return GestureDetector(
       onTap: onTap,
       child: Column(
@@ -88,18 +93,18 @@ class HomeSheet extends StatelessWidget {
             width: 72,
             height: 72,
             decoration: BoxDecoration(
-              color: AppColors.blue50,
+              color: colorScheme.primaryContainer,
               borderRadius: BorderRadius.circular(16),
             ),
-            child: Icon(icon, size: 32, color: AppColors.blue500),
+            child: Icon(icon, size: 32, color: colorScheme.primary),
           ),
           const SizedBox(height: 12),
           Text(
             label,
-            style: const TextStyle(
+            style: TextStyle(
               fontSize: 14,
               fontWeight: FontWeight.w500,
-              color: AppColors.slate700,
+              color: colorScheme.onSurfaceVariant,
             ),
           ),
         ],