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

apps/lib/shared/widgets/app_loading_indicator.dart

@@ -40,49 +40,46 @@ class AppLoadingIndicator extends StatelessWidget {
         };
   }
 
-  Color get _resolvedColor {
-    return color ??
-        switch (variant) {
-          AppLoadingVariant.surface => AppColors.blue500,
-          AppLoadingVariant.inline => AppColors.slate500,
-          AppLoadingVariant.button => AppColors.white,
-        };
-  }
-
-  Color get _resolvedTrackColor {
-    return trackColor ??
-        switch (variant) {
-          AppLoadingVariant.surface => AppColors.blue100,
-          AppLoadingVariant.inline => AppColors.slate200,
-          AppLoadingVariant.button => AppColors.blue300,
-        };
-  }
-
-  bool get _resolvedWithContainer {
-    return withContainer ??
-        switch (variant) {
-          AppLoadingVariant.surface => true,
-          AppLoadingVariant.inline => false,
-          AppLoadingVariant.button => false,
-        };
-  }
-
-  Widget _buildSpinner() {
+  Widget _buildSpinner(Color color, Color trackColor) {
     return SizedBox(
       width: _resolvedSize,
       height: _resolvedSize,
       child: CircularProgressIndicator(
         strokeWidth: _resolvedStrokeWidth,
-        color: _resolvedColor,
-        backgroundColor: _resolvedTrackColor,
+        color: color,
+        backgroundColor: trackColor,
       ),
     );
   }
 
   @override
   Widget build(BuildContext context) {
-    if (!_resolvedWithContainer) {
-      return _buildSpinner();
+    final colorScheme = Theme.of(context).colorScheme;
+
+    final resolvedColor =
+        color ??
+        switch (variant) {
+          AppLoadingVariant.surface => colorScheme.primary,
+          AppLoadingVariant.inline => colorScheme.onSurfaceVariant,
+          AppLoadingVariant.button => colorScheme.onPrimary,
+        };
+
+    final resolvedTrackColor =
+        trackColor ??
+        switch (variant) {
+          AppLoadingVariant.surface => colorScheme.primaryContainer,
+          AppLoadingVariant.inline => colorScheme.outlineVariant,
+          AppLoadingVariant.button => colorScheme.secondary,
+        };
+
+    if (withContainer == false ||
+        (withContainer == null &&
+            switch (variant) {
+              AppLoadingVariant.surface => true,
+              AppLoadingVariant.inline => false,
+              AppLoadingVariant.button => false,
+            })) {
+      return _buildSpinner(resolvedColor, resolvedTrackColor);
     }
 
     return Container(
@@ -90,18 +87,18 @@ class AppLoadingIndicator extends StatelessWidget {
       height: _resolvedSize + AppSpacing.md,
       padding: const EdgeInsets.all(AppSpacing.xs),
       decoration: BoxDecoration(
-        color: AppColors.white,
+        color: colorScheme.surface,
         borderRadius: BorderRadius.circular(AppRadius.full),
-        border: Border.all(color: AppColors.borderSecondary),
+        border: Border.all(color: colorScheme.outlineVariant),
         boxShadow: [
           BoxShadow(
-            color: AppColors.slate200.withValues(alpha: 0.55),
+            color: colorScheme.outlineVariant.withValues(alpha: 0.55),
             blurRadius: AppRadius.md,
             offset: const Offset(0, AppSpacing.xs),
           ),
         ],
       ),
-      child: _buildSpinner(),
+      child: _buildSpinner(resolvedColor, resolvedTrackColor),
     );
   }
 }