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

apps/lib/features/auth/presentation/widgets/auth_field.dart

@@ -29,16 +29,18 @@ class AuthField extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final colorScheme = Theme.of(context).colorScheme;
+
     return Column(
       crossAxisAlignment: CrossAxisAlignment.start,
       children: [
         if (label != null) ...[
           Text(
             label!,
-            style: const TextStyle(
+            style: TextStyle(
               fontSize: 13,
               fontWeight: FontWeight.w700,
-              color: AppColors.slate700,
+              color: colorScheme.onSurface,
             ),
           ),
           SizedBox(height: AppSpacing.sm),
@@ -52,15 +54,15 @@ class AuthField extends StatelessWidget {
             obscureText: obscureText,
             onChanged: onChanged,
             inputFormatters: inputFormatters,
-            style: const TextStyle(fontSize: 16, color: AppColors.slate900),
+            style: TextStyle(fontSize: 16, color: colorScheme.onSurface),
             decoration: InputDecoration(
               hintText: hint,
-              hintStyle: const TextStyle(
+              hintStyle: TextStyle(
                 fontSize: 15,
-                color: AppColors.slate400,
+                color: colorScheme.onSurfaceVariant,
               ),
               filled: true,
-              fillColor: AppColors.authInputBackground,
+              fillColor: colorScheme.surface,
               contentPadding: const EdgeInsets.symmetric(
                 horizontal: AppSpacing.lg,
                 vertical: AppSpacing.lg,
@@ -73,11 +75,11 @@ class AuthField extends StatelessWidget {
               ),
               enabledBorder: OutlineInputBorder(
                 borderRadius: BorderRadius.circular(AppRadius.lg),
-                borderSide: const BorderSide(color: AppColors.authInputBorder),
+                borderSide: BorderSide(color: colorScheme.outlineVariant),
               ),
               focusedBorder: OutlineInputBorder(
                 borderRadius: BorderRadius.circular(AppRadius.lg),
-                borderSide: const BorderSide(color: AppColors.authInputFocus),
+                borderSide: BorderSide(color: colorScheme.primary),
               ),
             ),
           ),