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_it.dart

@@ -827,6 +827,46 @@ class AppLocalizationsIt extends AppLocalizations {
   @override
   String get channels_sortUnread => 'Non letto';
 
+  @override
+  String get channels_createPrivateChannel => 'Crea un Canale Privato';
+
+  @override
+  String get channels_createPrivateChannelDesc =>
+      'Protetta con una chiave segreta.';
+
+  @override
+  String get channels_joinPrivateChannel => 'Unisciti a un Canale Privato';
+
+  @override
+  String get channels_joinPrivateChannelDesc =>
+      'Inserire manualmente una chiave segreta.';
+
+  @override
+  String get channels_joinPublicChannel => 'Unisciti al Canale Pubblico';
+
+  @override
+  String get channels_joinPublicChannelDesc =>
+      'Chiunque può unirsi a questo canale.';
+
+  @override
+  String get channels_joinHashtagChannel => 'Unisciti a un Canale con Hashtag';
+
+  @override
+  String get channels_joinHashtagChannelDesc =>
+      'Chiunque può unirsi ai canali hashtag.';
+
+  @override
+  String get channels_scanQrCode => 'Scansiona un codice QR';
+
+  @override
+  String get channels_scanQrCodeComingSoon => 'Arriverà presto';
+
+  @override
+  String get channels_enterHashtag => 'Inserisci hashtag';
+
+  @override
+  String get channels_hashtagHint => 'es. #team';
+
   @override
   String get chat_noMessages => 'Nessun messaggio ancora';