feat(design): a channel's and a Plex playlist's one action list (C1) — the row's "…", Delete + undo, an action toast's 8 s floor (E28 S3e2)

- Channels: the row's full-history, hide and unsubscribe buttons become its "…" at the row end
  (useChannelActions: open, pin, YouTube, copy name / link, full history or the admin reset,
  hide with an undo toast, unsubscribe behind its danger confirm); the card layout docks the "…"
  beside the name (ChannelLayoutGrid moreKey). The admin reset's confirm now names the reset.
- Plex playlist page: a title, a show group and a season each open the page's one row menu (a
  title's is its usePlexCardActions list plus the removal); no X at rest; removals take an undo
  toast whose Undo puts every row back at its own index in one request (bulk add `positions`);
  j/k walk the visible rows, Delete removes the walked one; rename and delete in the header's "…".
- notify: a toast with an action lives at least 8 s (the owner's call), whatever the toast setting.

frontend/src/i18n/locales/hu/plex.json

@@ -326,8 +326,14 @@
     "renameFailed": "Nem sikerült átnevezni a lejátszási listát.",
     "deleteFailed": "Nem sikerült törölni a lejátszási listát.",
     "reorderFailed": "Nem sikerült menteni az új sorrendet.",
-    "removeItem": "„{{title}}” eltávolítása a listáról",
-    "reorderItem": "„{{title}}” áthelyezése"
+    "reorderItem": "„{{title}}” áthelyezése",
+    "rowMenu": "Elem műveletei",
+    "menu": "Lista műveletei",
+    "playShow": "Sorozat lejátszása",
+    "playSeason": "Évad lejátszása",
+    "removeFromPlaylist": "Eltávolítás a listáról",
+    "removedToast": "„{{title}}” eltávolítva a listáról",
+    "undoRemoveFailed": "Nem sikerült visszatenni a listára."
   },
   "people": {
     "count_one": "{{count}} cím",