feat(render+admin): exports management (all users' rendered videos)

- render-svc: admin-scoped store (ListAllExports / GetExportByIDAny /
  SoftDeleteExportAny) + GET/DELETE/download-url under /v1/admin-exports
  (admin-gated; separate prefix so it routes to render, not identity's /admin)
- gateway: /v1/admin-exports/* → render
- admin /admin/exports: paginated table of every rendered export with thumbnail,
  type/quality, size, duration, dimensions, produce + expiry dates; download
  (presigned URL) and delete

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/[locale]/admin/exports/page.tsx

@@ -0,0 +1,7 @@
+"use client";
+
+import { ExportsAdmin } from "@/components/admin/ExportsAdmin";
+
+export default function Page() {
+  return <ExportsAdmin />;
+}

src/app/[locale]/admin/layout.tsx

@@ -42,6 +42,7 @@ export default async function AdminLayout({
     { href: "/admin/nodes", label: t("nodes") },
     { href: "/admin/node-fonts", label: t("nodeFonts") },
     { href: "/admin/renders", label: t("renderQueue") },
+    { href: "/admin/exports", label: t("exports") },
   ];
   return (
     <div className="min-h-screen bg-[#0c0e1a] text-gray-200">