fix(plex): Restart only where an episode has a resume point; the Surprise draw is re-read, not redrawn

Show cards carry resumable (ShowState, from the same rollup) so a part-watched
show whose next episode is untouched offers Play, not a Continue and a Restart
that do the same thing; plexStarted is the one rule for cards and menus. The
Surprise rail's key sits under the discover root: whatever refreshes the rails
re-reads the draw (keep=) with its watch state now, kept past the 5-minute gc,
and only the reshuffle deals. Closing the player refreshes the Discover rails.
A show card's play acts on the last click only, and only where it was made.

frontend/src/components/usePlexCardActions.tsx

@@ -39,9 +39,13 @@ export const plexAddLabelKey = (c: PlexCard): string =>
 const isPlexPlayable = (c: PlexCard): boolean => c.type !== "show";
 
 /** Has a resume point: the click continues it, and "from the start" is a choice. A watched item is
- *  stored at 0, so it never counts. */
+ *  stored at 0, so it never counts. A show has one when an episode does (`resumable`, the episode its
+ *  click plays): part watched with its next episode untouched, Continue and Restart would be the same
+ *  thing, so it is not "started" here — its in-progress badge says how far it has got. */
 export const plexStarted = (c: PlexCard): boolean =>
-  isPlexPlayable(c) && c.status !== "watched" && (c.position_seconds ?? 0) > 0;
+  isPlexPlayable(c)
+    ? c.status !== "watched" && (c.position_seconds ?? 0) > 0
+    : c.resumable === true;
 
 /** `open` is the host menu's own flag (the shelf is fetched only once a menu opened). Returns the
  *  item builder, `add` for the card's own hover button, and the dialog to render beside the menu
@@ -78,8 +82,7 @@ export function usePlexCardActions(handlers: PlexActionHandlers, open: boolean)
     const playable = isPlexPlayable(c);
     const isShow = c.type === "show";
     const watched = c.status === "watched";
-    // A show continues where its rollup says it stands, as its card's Continue + Restart do.
-    const started = isShow ? c.status === "in_progress" : plexStarted(c);
+    const started = plexStarted(c);
     return [
       ...(play
         ? [