feat(client/update): 更新提示改 jiu 式顶部横条(非强制不再弹窗)

按需求去掉居中弹窗,改成不打断的顶部 banner(对照 jiu 黄条):
- 非强制更新 → home_shell 顶部 UpdateBanner「发现新版本 vX + 立即更新 + ×」;
  「立即更新」App 内下载安装,「×」忽略此版本(banner 隐藏,更新版本会重现)
- 强制更新(force_update)→ 仍走不可关闭弹窗 showUpdateDialog
- 忽略状态改 dismissedUpdateVersionProvider(按版本号,响应式);去掉 notifier
  的 _dismissed
- 设置页「检查更新」有更新时:清忽略版本→banner 显示 + toast,不再弹窗
- 新增 6 语「立即更新」文案。flutter analyze 仅 2 个既有 withOpacity info

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013nMthbVEmQquxBRKb9Fj8u

client/lib/widgets/update_dialog.dart

@@ -6,10 +6,12 @@
 import 'dart:async';
 
 import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
 
 import '../core/update/app_updater.dart';
 import '../l10n/app_text.dart';
 import '../pangolin_theme.dart';
+import '../state/app_providers.dart';
 import '../state/update_provider.dart';
 import 'pangolin_icons.dart';
 
@@ -78,3 +80,60 @@ class _UpdateDialog extends StatelessWidget {
     );
   }
 }
+
+/// jiu 式顶部更新横条(非强制更新用;强制更新仍走不可关闭弹窗 showUpdateDialog)。
+/// 「立即更新」App 内下载安装;「×」忽略此版本(banner 隐藏,更新版本会重现)。
+class UpdateBanner extends ConsumerWidget {
+  const UpdateBanner({super.key, required this.info});
+  final AppUpdateInfo info;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final c = context.pangolin;
+    final t = ref.watch(appTextProvider);
+    return Material(
+      color: c.accentSubtle,
+      child: SafeArea(
+        bottom: false,
+        child: Padding(
+          padding: const EdgeInsets.fromLTRB(14, 8, 6, 8),
+          child: Row(children: [
+            Icon(PangolinIcons.zap, size: 17, color: c.accent),
+            const SizedBox(width: 10),
+            Expanded(
+              child: Text(
+                t.updateAvailableTitle(info.latestVersion),
+                style: PangolinText.sm.copyWith(color: c.fg1, fontWeight: FontWeight.w700),
+                overflow: TextOverflow.ellipsis,
+              ),
+            ),
+            const SizedBox(width: 8),
+            TextButton(
+              onPressed: () => unawaited(startInAppUpdate(context, t, info)),
+              style: TextButton.styleFrom(
+                backgroundColor: c.accent,
+                foregroundColor: c.fgOnAccent,
+                padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 6),
+                shape: RoundedRectangleBorder(
+                    borderRadius: BorderRadius.circular(PangolinRadius.full)),
+                minimumSize: Size.zero,
+                tapTargetSize: MaterialTapTargetSize.shrinkWrap,
+              ),
+              child: Text(t.lang.updateNow,
+                  style: PangolinText.caption
+                      .copyWith(fontWeight: FontWeight.w700, fontSize: 12.5)),
+            ),
+            IconButton(
+              onPressed: () =>
+                  ref.read(dismissedUpdateVersionProvider.notifier).state = info.latestVersion,
+              icon: Icon(Icons.close, size: 18, color: c.fg3),
+              padding: EdgeInsets.zero,
+              constraints: const BoxConstraints(minWidth: 36, minHeight: 36),
+              tooltip: t.updateLater,
+            ),
+          ]),
+        ),
+      ),
+    );
+  }
+}