Reapply "Add missing admin action files and navigation links"

This reverts commit 4d515bc400.

src/app/marketplace/page.tsx

@@ -66,11 +66,7 @@ export default async function MarketplacePage() {
 
   return (
     <main style={{ display: "grid", gap: "1.5rem" }}>
-      <ContentCard
-        icon="🛍️"
-        title={t("title")}
-        subtitle={t("subtitle")}
-      >
+      <ContentCard icon="🛍️" title={t("title")} subtitle={t("subtitle")}>
         <div className="stat-grid">
           <StatBlock value={offers.length.toLocaleString()} label={t("activeOffers")} icon="🏷️" />
           <StatBlock
@@ -89,9 +85,7 @@ export default async function MarketplacePage() {
         padded={offers.length === 0}
       >
         {offers.length === 0 ? (
-          <EmptyState icon="🛍️">
-            {t("empty")}
-          </EmptyState>
+          <EmptyState icon="🛍️">{t("empty")}</EmptyState>
         ) : (
           <div style={{ padding: "0.25rem 1rem 0.75rem", overflowX: "auto" }}>
             <table>