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/ConfigPanel.tsx

@@ -243,11 +243,11 @@ export default function ConfigPanel() {
                     </p>
                     {plexResult.media_check?.checked &&
                       (plexResult.media_check.ok ? (
-                        <p className="text-[11px] text-emerald-500 mb-2">
+                        <p className="text-[11px] text-success mb-2">
                           {t("config.plexMediaOk")}
                         </p>
                       ) : (
-                        <p className="text-[11px] text-red-400 mb-2">
+                        <p className="text-[11px] text-danger mb-2">
                           {t("config.plexMediaMissing", {
                             path: plexResult.media_check.local_path ?? "",
                           })}