Reapply "Add missing admin action files and navigation links"

This reverts commit 4d515bc400.

src/app/admin/email-templates/page.tsx

@@ -32,13 +32,15 @@ export default async function AdminEmailTemplates() {
         </div>
       </div>
 
-      <form
-        action={createEmailTemplate}
-        className="admin-card mb-6"
-      >
+      <form action={createEmailTemplate} className="admin-card mb-6">
         <h3 className="text-sm font-bold text-[var(--color-text)] mb-2">{t("newTemplate")}</h3>
         <div className="flex gap-2 flex-wrap items-center mb-3">
-          <input name="name" placeholder={t("form.namePlaceholder")} required className="flex-1 min-w-[180px]" />
+          <input
+            name="name"
+            placeholder={t("form.namePlaceholder")}
+            required
+            className="flex-1 min-w-[180px]"
+          />
           <input
             name="subject"
             placeholder={t("form.subjectPlaceholder")}
@@ -108,7 +110,9 @@ export default async function AdminEmailTemplates() {
                   </button>
                   {template.updatedAt ? (
                     <span className="text-xs text-gray-500 dark:text-gray-400">
-                      {t("updated", { date: new Date(template.updatedAt).toISOString().slice(0, 16).replace("T", " ") })}
+                      {t("updated", {
+                        date: new Date(template.updatedAt).toISOString().slice(0, 16).replace("T", " "),
+                      })}
                     </span>
                   ) : null}
                 </div>