parity(api,apps): delivery-mode gaps — master OTP, non-blocking SMS, faToEn, v2 cart cap

D20: OTP_MASTER_CODE login bypass read only from the environment, disabled when
unset, audited on every use, with a boot banner while armed. SMS no longer
aborts the boot in production — it warns and declines silently, so no message
can stop an operation.

D19: port Utility::faTOen onto admin-entered mobiles (before the uniqueness
lookup, which could previously be bypassed with Persian digits), and the
create-only welcome SMS, byte-identical to the reference and fire-and-forget.

user-app-v2 was missing the cart stock ceiling entirely: capQty/maxQty, the
un-orderable guard and the qty clamp are ported, leaving v2's own design intact.
The two cart stores are now byte-identical. isVariantOrderable and the
orderable-first default selection ported too.

jest 45/45; typecheck clean on api, admin-panel, user-app, user-app-v2.

[ref: henza_server/app/Http/Controllers/Adm/AdminController.php:333,348,364,378-387]
[ref: henza_server/app/Models/Utility.php:26]

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

apps/user-app/src/components/product/SingleProduct.vue

@@ -480,7 +480,10 @@ const decrement = () => {
 }
 
 const addToCart = () => {
-  cart.addToCart(storeProduct.value)
+  // The store refuses an un-orderable variant; only confirm when it accepted.
+  // Previously the "added to cart" toast fired either way, telling the customer
+  // something had been added when nothing had. Kept in step with user-app-v2.
+  if (!cart.addToCart(storeProduct.value)) return
   notify.value = true
 }