feat(admin): subscription expiry modals and once-per-session SMS warning

Co-authored-by: Cursor <cursoragent@cursor.com>

src/utils/serverUnavailable.ts

@@ -27,10 +27,7 @@ export function showServerUnavailableOverlay(message = MESSAGE) {
     <div style="position:fixed;inset:0;z-index:2147483000;display:flex;align-items:center;justify-content:center;direction:rtl;font-family:sans-serif;padding:24px;background:#ffffff;color:#111827;">
       <div style="width:min(420px,100%);text-align:center;background:#fff;border:1px solid rgba(15,23,42,0.08);border-radius:24px;padding:28px 22px;">
         <div style="font-size:42px;margin-bottom:12px;">⚠️</div>
-        <h2 style="margin:0 0 12px;font-size:20px;">${message}</h2>
-        <p style="margin:0 0 20px;color:rgba(15,23,42,0.62);line-height:2;font-size:14px;">
-          لطفاً چند لحظه دیگر دوباره تلاش کنید.
-        </p>
+        <h2 style="margin:0 0 20px;font-size:20px;">${message}</h2>
         <button
           type="button"
           onclick="location.reload()"