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

apps/lib/features/home/presentation/widgets/home_conversation_chrome.dart

@@ -11,6 +11,8 @@ class HomeWaitingIndicator extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final colorScheme = Theme.of(context).colorScheme;
+
     return Padding(
       padding: const EdgeInsets.fromLTRB(20, 0, 20, 20),
       child: Row(
@@ -19,18 +21,18 @@ class HomeWaitingIndicator extends StatelessWidget {
           SizedBox(
             width: 18,
             height: 18,
-            child: const AppLoadingIndicator(
+            child: AppLoadingIndicator(
               variant: AppLoadingVariant.inline,
               size: 18,
               strokeWidth: 2,
-              color: AppColors.blue600,
-              trackColor: AppColors.blue100,
+              color: colorScheme.primary,
+              trackColor: colorScheme.primaryContainer,
             ),
           ),
           SizedBox(width: AppSpacing.sm),
           Text(
             label,
-            style: const TextStyle(fontSize: 14, color: AppColors.slate500),
+            style: TextStyle(fontSize: 14, color: colorScheme.onSurfaceVariant),
           ),
         ],
       ),
@@ -45,6 +47,7 @@ class HomeDateDivider extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final colorScheme = Theme.of(context).colorScheme;
     final now = DateTime.now();
     const weekdays = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'];
     final weekday = weekdays[date.weekday - 1];
@@ -62,7 +65,7 @@ class HomeDateDivider extends StatelessWidget {
       alignment: Alignment.center,
       child: Text(
         label,
-        style: const TextStyle(fontSize: 12, color: AppColors.slate400),
+        style: TextStyle(fontSize: 12, color: colorScheme.onSurfaceVariant),
       ),
     );
   }
@@ -80,22 +83,27 @@ class HomeLoadMoreButton extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final colorScheme = Theme.of(context).colorScheme;
+
     return GestureDetector(
       onTap: isLoading ? null : onTap,
       child: Container(
         padding: const EdgeInsets.symmetric(vertical: 8),
         alignment: Alignment.center,
         child: isLoading
-            ? const AppLoadingIndicator(
+            ? AppLoadingIndicator(
                 variant: AppLoadingVariant.inline,
                 size: 14,
                 strokeWidth: 1.5,
-                color: AppColors.slate400,
-                trackColor: AppColors.slate200,
+                color: colorScheme.onSurfaceVariant,
+                trackColor: colorScheme.surfaceContainerHighest,
               )
             : Text(
                 context.l10n.homeViewHistory,
-                style: const TextStyle(fontSize: 12, color: AppColors.slate400),
+                style: TextStyle(
+                  fontSize: 12,
+                  color: colorScheme.onSurfaceVariant,
+                ),
               ),
       ),
     );