fix(i18n): every label a screen reader or tooltip says is translated

- The Plex playlist rows' "reorder"/"remove", the Plex filter chip's "remove" and the player
  slider's "reset" were English literals; each now names its row or setting in HU/EN.
- The playlist show header's chevron had no accessible name; its decorative thumbnail button left
  the tab order.
- The opt-in Glass tuner panel was English only: every word is translated, and each slider's label
  now names its number box and range.
- New `local/literal-a11y-text` lint rule (with its contract test): a literal word in aria-label,
  title, placeholder, alt and the other spoken/shown attributes fails lint.

frontend/src/components/PlexPlaylistView.tsx

@@ -128,12 +128,15 @@ function Poster({ src, className }: { src: string; className: string }) {
   );
 }
 
-function DragHandle(props: Record<string, unknown>) {
+/** `title` names the row it moves: a screen reader heard the English word "reorder" on every
+ *  row, with nothing to say which. */
+function DragHandle({ title, ...props }: { title: string } & Record<string, unknown>) {
+  const { t } = useTranslation();
   return (
     <button
       {...props}
       className="shrink-0 cursor-grab text-muted hover:text-fg active:cursor-grabbing"
-      aria-label="reorder"
+      aria-label={t("plex.playlist.reorderItem", { title })}
     >
       <GripVertical className="h-4 w-4" />
     </button>
@@ -141,6 +144,7 @@ function DragHandle(props: Record<string, unknown>) {
 }
 
 function EpisodeRow({ ep, ctx, dense }: { ep: PlexCard; ctx: Ctx; dense: boolean }) {
+  const { t } = useTranslation();
   const { attributes, listeners, setNodeRef, transform, transition, isDragging } = useSortable({
     id: ep.id,
     disabled: ctx.busy,
@@ -157,7 +161,7 @@ function EpisodeRow({ ep, ctx, dense }: { ep: PlexCard; ctx: Ctx; dense: boolean
       style={style}
       className={`flex items-center gap-2.5 rounded-lg ${dense ? "px-1.5 py-1" : "glass-card p-1.5"}`}
     >
-      <DragHandle {...attributes} {...listeners} />
+      <DragHandle title={ep.title} {...attributes} {...listeners} />
       <span className="w-5 shrink-0 text-center text-2xs text-muted tabular-nums">
         {ep.episode_number}
       </span>
@@ -185,7 +189,7 @@ function EpisodeRow({ ep, ctx, dense }: { ep: PlexCard; ctx: Ctx; dense: boolean
         onClick={() => ctx.onRemove([ep.id])}
         disabled={ctx.busy}
         className="shrink-0 rounded-sm p-1 text-muted hover:text-danger disabled:opacity-30"
-        aria-label="remove"
+        aria-label={t("plex.playlist.removeItem", { title: ep.title })}
       >
         <X className="h-4 w-4" />
       </FocusSafeButton>
@@ -194,6 +198,7 @@ function EpisodeRow({ ep, ctx, dense }: { ep: PlexCard; ctx: Ctx; dense: boolean
 }
 
 function MovieRow({ item, ctx }: { item: PlexCard; ctx: Ctx }) {
+  const { t } = useTranslation();
   const { attributes, listeners, setNodeRef, transform, transition, isDragging } = useSortable({
     id: item.id,
     disabled: ctx.busy,
@@ -210,7 +215,7 @@ function MovieRow({ item, ctx }: { item: PlexCard; ctx: Ctx }) {
       style={style}
       className="glass-card flex items-center gap-3 rounded-xl p-2"
     >
-      <DragHandle {...attributes} {...listeners} />
+      <DragHandle title={item.title} {...attributes} {...listeners} />
       <button
         onClick={() => ctx.onPlay(item.id)}
         className="group flex min-w-0 flex-1 items-center gap-3 text-left"
@@ -228,7 +233,7 @@ function MovieRow({ item, ctx }: { item: PlexCard; ctx: Ctx }) {
         onClick={() => ctx.onRemove([item.id])}
         disabled={ctx.busy}
         className="shrink-0 rounded-sm p-1 text-muted hover:text-danger disabled:opacity-30"
-        aria-label="remove"
+        aria-label={t("plex.playlist.removeItem", { title: item.title })}
       >
         <X className="h-4 w-4" />
       </FocusSafeButton>
@@ -258,16 +263,24 @@ function ShowGroup({ block, ctx }: { block: Extract<Block, { kind: "show" }>; ct
     <div ref={setNodeRef} style={style} className="glass-card overflow-hidden rounded-xl">
       {/* Group header — drag moves the whole show; chevron collapses; X removes the whole show. */}
       <div className="flex items-center gap-2.5 p-2">
-        <DragHandle {...attributes} {...listeners} />
+        <DragHandle title={block.title} {...attributes} {...listeners} />
         <button
           onClick={() => ctx.toggleShow(block.showKey)}
           className="grid h-6 w-6 shrink-0 place-items-center rounded-sm text-muted hover:text-fg"
           aria-expanded={open}
+          aria-label={block.title}
         >
           {open ? <ChevronDown className="h-4 w-4" /> : <ChevronRight className="h-4 w-4" />}
         </button>
         {!dense && (
-          <button onClick={() => ctx.toggleShow(block.showKey)} className="flex shrink-0">
+          // A second, pointer-only target for the same toggle (its images are decorative): out of
+          // the tab order, so the keyboard does not stop on a button with no name.
+          <button
+            onClick={() => ctx.toggleShow(block.showKey)}
+            className="flex shrink-0"
+            tabIndex={-1}
+            aria-hidden
+          >
             {block.items.slice(0, 3).map((ep, i) => (
               <img
                 key={ep.id}