Add support for private and hashtag channels in localization and channel management

- Updated Polish, Portuguese, Slovak, Slovenian, Swedish, and Chinese localization files to include new strings for creating and joining private channels, as well as joining hashtag channels.
- Enhanced the channel management UI to allow users to create and join private channels, join public channels, and join channels via hashtags.
- Implemented PSK derivation from hashtags using SHA256 in the Channel model.
- Improved the translation script to handle missing keys and translate all locales efficiently.

lib/l10n/app_localizations_zh.dart

@@ -789,6 +789,42 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get channels_sortUnread => '未读';
 
+  @override
+  String get channels_createPrivateChannel => '创建私聊频道';
+
+  @override
+  String get channels_createPrivateChannelDesc => '使用密钥保护。';
+
+  @override
+  String get channels_joinPrivateChannel => '加入私密频道';
+
+  @override
+  String get channels_joinPrivateChannelDesc => '手动输入密钥。';
+
+  @override
+  String get channels_joinPublicChannel => '加入公共频道';
+
+  @override
+  String get channels_joinPublicChannelDesc => '任何人都可以加入这个频道。';
+
+  @override
+  String get channels_joinHashtagChannel => '加入标签频道';
+
+  @override
+  String get channels_joinHashtagChannelDesc => '任何人都可以加入话题频道。';
+
+  @override
+  String get channels_scanQrCode => '扫描二维码';
+
+  @override
+  String get channels_scanQrCodeComingSoon => '即将到来';
+
+  @override
+  String get channels_enterHashtag => '输入标签';
+
+  @override
+  String get channels_hashtagHint => '例如 #团队';
+
   @override
   String get chat_noMessages => '目前还没有消息';