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/SettingsPanel.tsx

@@ -117,12 +117,12 @@ function SaveIndicator({ state }: { state: PrefsSaveState }) {
           {t("settings.save.saving")}
         </span>
       ) : state === "saved" ? (
-        <span className="inline-flex items-center gap-1.5 text-emerald-500">
+        <span className="inline-flex items-center gap-1.5 text-success">
           <Check className="w-4 h-4" />
           {t("settings.save.saved")}
         </span>
       ) : (
-        <span className="text-red-500">{t("settings.save.failed")}</span>
+        <span className="text-danger">{t("settings.save.failed")}</span>
       )}
     </div>
   );
@@ -480,7 +480,7 @@ function SignInMethods({ me }: { me: Me }) {
               autoComplete="new-password"
               className={inputCls}
             />
-            {err && <p className="text-xs text-red-400">{err}</p>}
+            {err && <p className="text-xs text-danger">{err}</p>}
             <button
               type="submit"
               disabled={busy || !next}
@@ -680,7 +680,7 @@ function Account({ me, onOpenWizard }: { me: Me; onOpenWizard: () => void }) {
           </p>
           <button
             onClick={onDeleteAccount}
-            className="inline-flex items-center gap-1.5 px-3 py-2 rounded-xl text-sm border border-red-500/40 text-red-400 hover:bg-red-500/10 transition"
+            className="inline-flex items-center gap-1.5 px-3 py-2 rounded-xl text-sm border border-danger/40 text-danger hover:bg-danger/10 transition"
           >
             <Trash2 className="w-4 h-4" />
             {t("settings.account.deleteAccount")}