feat(theme): R10 S1 — semantic status colors (danger/warn/success)

Add theme-scoped --danger/--warn/--success (+ -fg) tokens wired into the v4
@theme inline, replacing ~110 raw red/amber/emerald/green palette refs across
34 files. Fixes light-theme contrast failures (fixed Tailwind shades fell to
~1.7-3:1 on white). Status colors are scheme-independent — recognised by hue,
shifting only by theme to hold contrast (bright on dark bg, darkened on light).
Solid fills use the paired -fg text; @source inline guarantees the full -fg set
exists. IMDb rating gold kept as a deliberate decorative non-status exception.

frontend/src/components/PlexPlaylistView.tsx

@@ -179,7 +179,7 @@ function EpisodeRow({ ep, ctx, dense }: { ep: PlexCard; ctx: Ctx; dense: boolean
       <button
         onClick={() => ctx.onRemove([ep.id])}
         disabled={ctx.busy}
-        className="shrink-0 rounded-sm p-1 text-muted hover:text-red-400 disabled:opacity-30"
+        className="shrink-0 rounded-sm p-1 text-muted hover:text-danger disabled:opacity-30"
         aria-label="remove"
       >
         <X className="h-4 w-4" />
@@ -222,7 +222,7 @@ function MovieRow({ item, ctx }: { item: PlexCard; ctx: Ctx }) {
       <button
         onClick={() => ctx.onRemove([item.id])}
         disabled={ctx.busy}
-        className="shrink-0 rounded-sm p-1 text-muted hover:text-red-400 disabled:opacity-30"
+        className="shrink-0 rounded-sm p-1 text-muted hover:text-danger disabled:opacity-30"
         aria-label="remove"
       >
         <X className="h-4 w-4" />
@@ -285,7 +285,7 @@ function ShowGroup({ block, ctx }: { block: Extract<Block, { kind: "show" }>; ct
           onClick={() => ctx.onRemove(block.items.map((i) => i.id))}
           disabled={ctx.busy}
           title={t("plex.playlist.removeShow")}
-          className="shrink-0 rounded-sm p-1 text-muted hover:text-red-400 disabled:opacity-30"
+          className="shrink-0 rounded-sm p-1 text-muted hover:text-danger disabled:opacity-30"
         >
           <X className="h-4 w-4" />
         </button>
@@ -323,7 +323,7 @@ function ShowGroup({ block, ctx }: { block: Extract<Block, { kind: "show" }>; ct
                       onClick={() => ctx.onRemove(s.items.map((i) => i.id))}
                       disabled={ctx.busy}
                       title={t("plex.playlist.removeSeason")}
-                      className="ml-1 rounded-sm p-0.5 text-muted hover:text-red-400 disabled:opacity-30"
+                      className="ml-1 rounded-sm p-0.5 text-muted hover:text-danger disabled:opacity-30"
                     >
                       <X className="h-3.5 w-3.5" />
                     </button>
@@ -572,7 +572,7 @@ export default function PlexPlaylistView({
           <button
             onClick={del}
             title={t("plex.playlist.delete")}
-            className="glass-card glass-hover rounded-lg p-2 text-sm hover:text-red-400"
+            className="glass-card glass-hover rounded-lg p-2 text-sm hover:text-danger"
           >
             <Trash2 className="h-4 w-4" />
           </button>