feat(jellyfin): the player as players are, with the settings under a cog

The Watch screen's player takes the shape people know from players,
YouTube's first: the picture set in from every side with rounded
corners, so the glow of its colours shows all around it, and over it
play or pause in the middle with 10 seconds back and on beside it, and
along its foot where the video is (0:05 ──── 23:47) and a cog. The
controls fade out while it plays and the pointer rests, and come back as
it moves, on a tap with a finger, on a jump and while paused. The cog
opens a panel inside the picture, so nothing runs off the window: Pause
after each line, the subtitles, the translation and the sound, each
track named by its language in the app's words, and the keyboard
shortcuts. The buttons for the line before, again and the next sit
beside the subtitles they act on, no longer looking like a player's
skip to the next video. Keys are YouTube's (Space or K, J and L, the
arrows, 0 to 9, Home, End) with Shift and the arrows for lines, R, P and
Esc; ? lists them.

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

@@ -1774,13 +1774,29 @@
   "watchSubtitles": "Untertitel",
   "watchTranslation": "Übersetzung",
   "watchAudio": "Audio",
-  "watchTracks": "Audio und Untertitel",
+  "watchBack10": "10 Sekunden zurück",
+  "watchForward10": "10 Sekunden vor",
+  "watchSettings": "Einstellungen",
+  "watchShortcuts": "Tastenkürzel",
+  "watchTrackForced": "erzwungen",
+  "watchTrackCaptions": "für Hörgeschädigte",
+  "watchKeyPlayPause": "Abspielen oder pausieren",
+  "watchKeyFive": "5 Sekunden zurück oder vor",
+  "watchKeyTen": "10 Sekunden zurück oder vor",
+  "watchKeyLines": "Vorige oder nächste Zeile",
+  "watchKeyJump": "Zu 0 %, 10 %, … 90 % des Videos",
+  "watchKeyStartEnd": "Zum Anfang oder zum Ende",
+  "watchKeyClose": "Wort oder Einstellungen schließen",
+  "watchKeyShortcuts": "Diese Tastenkürzel",
+  "watchKeySpace": "Leertaste",
+  "watchKeyShift": "Umschalt",
+  "watchKeyHome": "Pos1",
+  "watchKeyEnd": "Ende",
   "watchNone": "Keine",
   "watchPlay": "Abspielen",
   "watchPause": "Pause",
   "watchPreviousLine": "Vorherige Zeile",
   "watchNextLine": "Nächste Zeile",
-  "watchRepeatLine": "Zeile wiederholen",
   "watchPauseAtLineEnd": "Nach jeder Zeile anhalten",
   "watchWordsTitle": "Wörter in diesem Video",
   "watchWordsNewOnly": "Nur neue",