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_de.arb

@@ -597,8 +597,8 @@
   "tagManageAdd": "Tag hinzufügen",
   "tagManageRow": "{name} ({count})",
   "tagManageEdit": "Tag bearbeiten",
-  "tagManageHide": "Auf Karten ausblenden",
-  "tagManageShow": "Auf Karten zeigen",
+  "tagManageHideJellyfin": "Tags aus Jellyfin beim Lernen ausblenden",
+  "tagManageHideJellyfinHint": "Die Serien, Folgen, Künstler und Songs, in denen Wörter vorkamen. Sie bleiben an den Karten, zum Filtern und Lernen.",
   "tagManageDelete": "Tag löschen",
   "tagDeleteTitle": "Tag „{name}“ löschen?",
   "tagDeleteMessage": "{count, plural, =0{Er ist an keiner Karteikarte.} =1{Er wird auf all deinen Geräten von 1 Karteikarte entfernt.} other{Er wird auf all deinen Geräten von {count} Karteikarten entfernt.}}",
@@ -1833,7 +1833,7 @@
   "watchWordsFinding": "Wörter werden gesucht …",
   "watchWordCount": "{count}×",
   "watchAdd": "Hinzufügen",
-  "watchAdded": "{word} hinzugefügt, mit dieser Zeile",
+  "watchAdded": "{word} hinzugefügt",
   "watchTapAWord": "Tipp auf ein Wort der Untertitel, um es nachzuschlagen.",
   "watchFormOf": "Eine Form von {word}",
   "watchFailed": "Das Video konnte nicht abgespielt werden."