feat(flutter): 统一二级页头并恢复新剧暖色

lib/pages/reserve/reserve_page.dart

@@ -3,6 +3,7 @@
 import 'package:flutter/material.dart';
 
 import '../../core/theme/app_colors.dart';
+import '../../core/widgets/subpage_header.dart';
 import '../../l10n/app_localizations.dart';
 import '../new_releases/new_releases_page.dart';
 
@@ -43,7 +44,11 @@ class _ReservePageState extends State<ReservePage> {
         child: ListView(
           padding: const EdgeInsets.fromLTRB(0, 4, 0, 24),
           children: [
-            _header(context, l10n),
+            AppSubpageHeader(
+              title: l10n.reserveTitle,
+              subtitle: l10n.reserveSubtitle,
+              backKey: const Key('reserve-back'),
+            ),
             Padding(
               padding: const EdgeInsets.fromLTRB(16, 8, 16, 0),
               child: _weekStrip(l10n),
@@ -62,48 +67,6 @@ class _ReservePageState extends State<ReservePage> {
     );
   }
 
-  Widget _header(BuildContext context, AppLocalizations l10n) {
-    return Padding(
-      padding: const EdgeInsets.fromLTRB(6, 0, 16, 0),
-      child: Column(
-        crossAxisAlignment: CrossAxisAlignment.start,
-        children: [
-          Row(
-            children: [
-              IconButton(
-                key: const Key('reserve-back'),
-                tooltip: MaterialLocalizations.of(context).backButtonTooltip,
-                onPressed: () => Navigator.of(context).maybePop(),
-                icon: const Icon(
-                  Icons.chevron_left_rounded,
-                  color: AppColors.onSurface,
-                  size: 26,
-                ),
-              ),
-              Expanded(
-                child: Text(
-                  l10n.reserveTitle,
-                  style: const TextStyle(
-                    color: AppColors.onSurface,
-                    fontSize: 24,
-                    fontWeight: FontWeight.w800,
-                  ),
-                ),
-              ),
-            ],
-          ),
-          Padding(
-            padding: const EdgeInsets.only(left: 8),
-            child: Text(
-              l10n.reserveSubtitle,
-              style: const TextStyle(color: AppColors.muted, fontSize: 12),
-            ),
-          ),
-        ],
-      ),
-    );
-  }
-
   Widget _weekStrip(AppLocalizations l10n) {
     return Column(
       crossAxisAlignment: CrossAxisAlignment.start,