feat(flutter): 接入分类记录收藏与下载授权

lib/core/widgets/auth_gate.dart

@@ -9,9 +9,7 @@ import '../theme/app_colors.dart';
 /// 打开登录 / 注册页（沿用现有 Navigator 风格，不引路由库）
 Future<void> openAuthPage(BuildContext context, {bool signUpMode = false}) {
   return Navigator.of(context).push(
-    MaterialPageRoute<void>(
-      builder: (_) => AuthPage(signUpMode: signUpMode),
-    ),
+    MaterialPageRoute<void>(builder: (_) => AuthPage(signUpMode: signUpMode)),
   );
 }
 
@@ -81,3 +79,44 @@ Future<bool> ensureSignedIn(BuildContext context) async {
   }
   return false;
 }
+
+/// 页面级登录引导，用于记录、收藏和下载等必须登录的独立页面。
+class AuthGatePanel extends StatelessWidget {
+  const AuthGatePanel({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context)!;
+    return Center(
+      key: const Key('auth-gate-panel'),
+      child: Padding(
+        padding: const EdgeInsets.symmetric(horizontal: 32),
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            Text(
+              l10n.authGateTitle,
+              textAlign: TextAlign.center,
+              style: const TextStyle(
+                color: Colors.white,
+                fontSize: 18,
+                fontWeight: FontWeight.w800,
+              ),
+            ),
+            const SizedBox(height: 8),
+            Text(
+              l10n.authGateMessage,
+              textAlign: TextAlign.center,
+              style: const TextStyle(color: AppColors.muted, fontSize: 13),
+            ),
+            const SizedBox(height: 18),
+            FilledButton(
+              onPressed: () => openAuthPage(context),
+              child: Text(l10n.authGateAction),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}

lib/core/widgets/download_action.dart

@@ -0,0 +1,29 @@
+// Author: fruit.com.cn
+
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+
+import '../../l10n/app_localizations.dart';
+import '../data/services/download_controller.dart';
+import 'auth_gate.dart';
+
+/// 详情页与播放页共用的下载授权入口。
+///
+/// 未登录先走登录闸；业务拒绝时直接展示后端 message。
+Future<void> requestEpisodeDownload(
+  BuildContext context,
+  String episodeId,
+) async {
+  if (!await ensureSignedIn(context)) return;
+  if (!context.mounted) return;
+  final result = await context.read<DownloadController>().grant(episodeId);
+  if (!context.mounted) return;
+  final l10n = AppLocalizations.of(context)!;
+  final hasBackendMessage = result.message?.trim().isNotEmpty ?? false;
+  final message = result.ok
+      ? l10n.downloadGranted
+      : hasBackendMessage
+      ? result.message!
+      : l10n.downloadGrantFailed;
+  ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(message)));
+}

lib/core/widgets/library_drama_tile.dart

@@ -0,0 +1,73 @@
+// Author: fruit.com.cn
+
+import 'package:flutter/material.dart';
+
+import '../data/models/drama.dart';
+import '../theme/app_colors.dart';
+import 'remote_image.dart';
+
+/// 收藏等账号列表复用的剧集卡片，视觉与"我的"页列表保持一致。
+class LibraryDramaTile extends StatelessWidget {
+  const LibraryDramaTile({
+    super.key,
+    required this.drama,
+    required this.onTap,
+    this.trailing,
+  });
+
+  final Drama drama;
+  final VoidCallback? onTap;
+  final Widget? trailing;
+
+  @override
+  Widget build(BuildContext context) {
+    return Material(
+      color: const Color(0xFF1B1C21),
+      borderRadius: BorderRadius.circular(12),
+      clipBehavior: Clip.antiAlias,
+      child: InkWell(
+        onTap: onTap,
+        child: Padding(
+          padding: const EdgeInsets.all(9),
+          child: Row(
+            children: [
+              ClipRRect(
+                borderRadius: BorderRadius.circular(8),
+                child: RemoteImage(drama.posterUrl, width: 74, height: 103),
+              ),
+              const SizedBox(width: 11),
+              Expanded(
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      drama.title,
+                      maxLines: 2,
+                      overflow: TextOverflow.ellipsis,
+                      style: const TextStyle(
+                        color: Colors.white,
+                        fontSize: 15,
+                        fontWeight: FontWeight.w700,
+                      ),
+                    ),
+                    const SizedBox(height: 7),
+                    Text(
+                      drama.genre.isEmpty ? drama.category : drama.genre,
+                      maxLines: 1,
+                      overflow: TextOverflow.ellipsis,
+                      style: const TextStyle(
+                        color: AppColors.muted,
+                        fontSize: 12,
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+              ?trailing,
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}