feat(tag): one switch hides the tags from Jellyfin while studying

Every tag the app makes for where words were met on Jellyfin (the show
and the episode, the artist and the song) now says so (`origin` in tag
schema 2, written only for such a tag), in place of a tag hidden one by
one. Manage tags, where there are such tags, has one switch, Hide tags
from Jellyfin while studying (`hideJellyfinTags`, settings schema 9,
following the person): with it on, cards being studied leave them out of
their row at once, and Tags and Manage tags list them faint. They still
filter and narrow a session. The per-tag eye button is gone.

A word added while watching no longer takes the line it was met in as
its first hint: its hints are the dictionary's examples alone. Tatoeba's
sentences are checked, a subtitle line may be wrong or mistyped, a word
met again in a better line wouldn't get it, and every episode's line
would pile up on a common word.

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_en.arb

@@ -674,8 +674,8 @@
   "tagManageRow": "{name} ({count})",
   "@tagManageRow": {"description": "A tag in the list of tags, with how many flashcards have it.", "placeholders": {"name": {"type": "String"}, "count": {"type": "int"}}},
   "tagManageEdit": "Edit tag",
-  "tagManageHide": "Hide on cards",
-  "tagManageShow": "Show on cards",
+  "tagManageHideJellyfin": "Hide tags from Jellyfin while studying",
+  "tagManageHideJellyfinHint": "The shows, episodes, artists and songs words were met in. They stay on the cards, to filter and study by.",
   "tagManageDelete": "Delete tag",
   "tagDeleteTitle": "Delete the tag '{name}'?",
   "@tagDeleteTitle": {"placeholders": {"name": {"type": "String"}}},
@@ -2148,7 +2148,7 @@
   "watchWordCount": "{count}×",
   "@watchWordCount": {"placeholders": {"count": {"type": "int"}}},
   "watchAdd": "Add",
-  "watchAdded": "{word} added, with this line",
+  "watchAdded": "{word} added",
   "@watchAdded": {"placeholders": {"word": {"type": "String"}}},
   "watchTapAWord": "Tap a word of the subtitles to look it up.",
   "watchFormOf": "A form of {word}",