feat(jellyfin): an episode's own tag, and studying an episode's words

A word added from an episode gets the show's tag and the episode's own ("あかね噺 S1 E1"), hidden on cards. The words panel's Study button studies the studyset's cards of the video's words, on their schedules or crammed (each once): it pauses the video and first gives the episode's tag to the cards of its words the studyset held before, then opens the session on that tag. A study focus can now ask for cramming.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

halkyon_learn_flutter/lib/l10n/app_localizations_en.dart

@@ -6633,6 +6633,22 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get watchWider => 'Longer words here';
 
+  @override
+  String get watchStudy => 'Study';
+
+  @override
+  String get watchStudyWords => 'Study this video\'s words';
+
+  @override
+  String get watchStudyNothing =>
+      'The studyset holds none of this video\'s words yet';
+
+  @override
+  String get watchStudyScheduled => 'Study, on their schedules';
+
+  @override
+  String get watchStudyCram => 'Cram, each once';
+
   @override
   String get watchFilter => 'Filter the words';