fix: menu item/category create, demo banner reach, token refresh, blog publish

Dashboard & API bug fixes for owner-reported breakage:

- MenuController validators (PosValidators): NameEn was required but the
  dashboard sends null when blank, so every manual menu-item create failed
  and category create failed 100% (the form never sends nameEn). Now optional.
- DemoDataBanner: only showed when a cafe was exactly empty, so
  showcase-seeded cafes (2-3 cats / 3-5 items) could never trigger the
  one-click seed. Widened gate to sparse menus (<5 cats && <10 items) and
  added a clear "nothing to add" message when already populated.
- client.ts: added one-time JWT refresh-and-retry on 401 (shared in-flight
  promise) before bouncing to /login. Expired access tokens silently broke
  ticket list, add-table, and other reads.
- Surface API errors as toasts on menu + table mutations (were swallowed
  silently, so failures looked like "nothing happens").
- Admin blog editor: saving an edit dropped IsPublished (defaulted false,
  silently unpublishing the post on every save); now persisted with a
  toggle. Also hoisted the inner Field component to module scope - it was
  remounting every input on each keystroke and dropping focus.
- Admin integrations: replaced raw radio gateway selector with a styled
  RadioDot matching the iOS toggles.

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

web/dashboard/src/components/demo/demo-data-banner.tsx

@@ -43,6 +43,12 @@ export function DemoDataBanner({ invalidateKeys, className }: Props) {
 
   if (!cafeId || (role !== "Owner" && role !== "Manager")) return null;
   if (done && summary) {
+    const nothingAdded =
+      summary.categoriesAdded === 0 &&
+      summary.itemsAdded === 0 &&
+      summary.tablesAdded === 0 &&
+      summary.ingredientsAdded === 0 &&
+      !summary.taxCreated;
     return (
       <div
         className={cn(
@@ -52,10 +58,16 @@ export function DemoDataBanner({ invalidateKeys, className }: Props) {
       >
         <Sparkles className="size-4 shrink-0" />
         <span>
-          داده‌های نمونه اضافه شد — {summary.categoriesAdded} دسته،{" "}
-          {summary.itemsAdded} آیتم، {summary.tablesAdded} میز،{" "}
-          {summary.ingredientsAdded} ماده اولیه
-          {summary.taxCreated ? "، مالیات ۹٪" : ""}.
+          {nothingAdded ? (
+            "همه داده‌های نمونه از قبل موجود بودند — موردی اضافه نشد."
+          ) : (
+            <>
+              داده‌های نمونه اضافه شد — {summary.categoriesAdded} دسته،{" "}
+              {summary.itemsAdded} آیتم، {summary.tablesAdded} میز،{" "}
+              {summary.ingredientsAdded} ماده اولیه
+              {summary.taxCreated ? "، مالیات ۹٪" : ""}.
+            </>
+          )}
         </span>
       </div>
     );