fix(theme): R10 S1 review fixes — restore distinctions lost in the codemod

- PlexBrowse PLAYABLE_TINT: transcode was collapsed onto remux's bg-warn; give it
  bg-danger so direct/remux/transcode read as a distinct good->heavy green/amber/red
  gradient again.
- Live indicators (VideoCard row + thumbnail badge, playlistColumns badge): revert to
  fixed live-red + white instead of the --danger token. 'live' is a broadcast marker,
  not an error state, and the badge sits over a thumbnail (no app-bg contrast need);
  restores the conventional red/white LIVE look and decouples it from error retunes.
- ChannelPage exploring badge: drop the redundant dark:text-warn (no-op after the
  token rename — --warn is already theme-scoped).

error/fatal toast shade merge left as-is (both are 'bad'; the 400/500 step was subtle).

frontend/src/components/PlexBrowse.tsx

@@ -430,10 +430,13 @@ export default function PlexBrowse() {
   );
 }
 
+// Playback cost, escalating good→heavy: direct (green) → remux, a light repackage
+// (amber) → transcode, a full re-encode (red). Reuses the status trio as a gradient;
+// all three stay visually distinct.
 const PLAYABLE_TINT: Record<string, string> = {
   direct: "bg-success",
   remux: "bg-warn",
-  transcode: "bg-warn",
+  transcode: "bg-danger",
 };
 
 function PlexPosterCard({