fix(dashboard): review fixes — error toasts, dedupe socket, POS guards

- Global MutationCache.onError safety net so mutations without their own onError
  no longer fail silently (skips ones that handle errors → no double toast).
- Notifications feed no longer opens its own SignalR connection; it reuses the
  one in useOrderAlerts (was double sockets + double cache churn per session).
- "Send test notification" now works on the settings page (force flag bypasses
  the tab-visible guard) instead of silently doing nothing.
- POS: re-entry guard on payment confirm (no duplicate payment on double-tap);
  notes on already-sent lines are read-only (a note-only edit was silently lost);
  ORDER_ALREADY_CLOSED surfaced with a clear Persian message.
- Reservation Confirm/Cancel/Complete buttons disabled while pending.

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

web/dashboard/src/components/pos2/pos2-screen.tsx

@@ -7,7 +7,7 @@
 // Mounted at /[locale]/pos (and /pos2). Design mirrors pos2-prototype.tsx.
 // ─────────────────────────────────────────────────────────────────────────────
 
-import { useEffect, useMemo, useState } from "react";
+import { useEffect, useMemo, useRef, useState } from "react";
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import {
   Search, Plus, Minus, Trash2, Send, CreditCard, SplitSquareHorizontal,
@@ -123,6 +123,7 @@ export function Pos2Screen() {
   const [payLoyalty, setPayLoyalty] = useState(0);
   // Order just paid — kept after the cart is cleared so the receipt stays printable.
   const [paidOrderId, setPaidOrderId] = useState<string | null>(null);
+  const payingRef = useRef(false); // re-entry guard for the payment confirm
 
   const [online, setOnline] = useState(true);
   useEffect(() => {
@@ -275,7 +276,8 @@ export function Pos2Screen() {
   };
 
   const confirmPay = async (payments: Payment[], loyaltyRedeem: number) => {
-    if (!payTarget) return;
+    if (!payTarget || payingRef.current) return; // guard against a double-tap
+    payingRef.current = true;
     setBusy(true);
     try {
       const cardTotal = payments.filter((p) => p.method === "Card").reduce((s, p) => s + p.amount, 0);
@@ -306,10 +308,13 @@ export function Pos2Screen() {
         notify.error(posDeviceMsg(e));
       } else if (e instanceof ApiClientError && e.code === "NO_OPEN_SHIFT") {
         notify.error("برای پرداخت باید شیفت باز باشد");
+      } else if (e instanceof ApiClientError && e.code === "ORDER_ALREADY_CLOSED") {
+        notify.error("این سفارش قبلاً تسویه شده است");
       } else {
         notify.error(errMsg(e, "ثبت پرداخت ناموفق بود"));
       }
     } finally {
+      payingRef.current = false;
       setBusy(false);
     }
   };
@@ -355,7 +360,11 @@ export function Pos2Screen() {
   );
 
   const ticketProps = {
-    cafeId, lines: live, subtotal, discount, tax, total, count, pendingCount,
+    cafeId,
+    // mark fully-sent lines so their note becomes read-only (a note-only change on
+    // an already-sent line would otherwise be silently dropped on the next send).
+    lines: live.map((l) => ({ ...l, synced: (syncedQty[l.menuItem.id] ?? 0) >= l.quantity })),
+    subtotal, discount, tax, total, count, pendingCount,
     onBump: (id: string, d: number) => { const l = items.find((x) => x.menuItem.id === id); if (l) updateQty(id, l.quantity + d); },
     onRemove: removeItem, onSend: send, onPay: openPay, onSplit: openPay,
     onNote: (id: string, notes: string) => setNotes(id, notes),
@@ -732,7 +741,7 @@ function Pos2Extras({ cafeId }: { cafeId: string }) {
 }
 
 // ── Order ticket ─────────────────────────────────────────────────────────────
-type TicketLine = { menuItem: MenuItem; quantity: number; notes?: string };
+type TicketLine = { menuItem: MenuItem; quantity: number; notes?: string; synced?: boolean };
 function Ticket({
   cafeId, lines, subtotal, discount, tax, total, count, pendingCount, onBump, onRemove, onNote, onSend, onPay, onSplit, canPrint, onPrintReceipt,
 }: {
@@ -775,7 +784,14 @@ function Ticket({
                     <Trash2 className="size-4" />
                   </button>
                 </div>
-                {noteFor === l.menuItem.id || l.notes ? (
+                {l.synced ? (
+                  // Already sent to the kitchen — note is read-only (can't be changed now).
+                  l.notes ? (
+                    <p className="mt-1.5 flex items-center gap-1.5 text-xs text-muted-foreground">
+                      <StickyNote className="size-3.5 shrink-0" /> {l.notes}
+                    </p>
+                  ) : null
+                ) : noteFor === l.menuItem.id || l.notes ? (
                   <input
                     value={l.notes ?? ""}
                     onChange={(e) => onNote(l.menuItem.id, e.target.value)}

web/dashboard/src/components/providers.tsx

@@ -1,16 +1,31 @@
 "use client";
 
-import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import { QueryClient, QueryClientProvider, MutationCache } from "@tanstack/react-query";
 import { useEffect, useState } from "react";
 import { ConfirmProvider } from "@/components/providers/confirm-provider";
 import { MeeziToaster } from "@/components/ui/meezi-toaster";
 import { useAuthStore } from "@/lib/stores/auth.store";
 import { restoreQueryCache, startPersisting } from "@/lib/offline/query-persister";
+import { notify, getErrorMessage } from "@/lib/notify";
+
+/** Generic, locale-aware fallback for mutations that don't handle their own error. */
+function globalMutationErrorFallback(): string {
+  const lang = typeof document !== "undefined" ? document.documentElement.lang : "fa";
+  return lang === "en" ? "Something went wrong" : lang === "ar" ? "حدث خطأ ما" : "خطایی رخ داد";
+}
 
 export function Providers({ children }: { children: React.ReactNode }) {
   const [queryClient] = useState(
     () =>
       new QueryClient({
+        // Safety net: surface a toast for any mutation that doesn't define its own
+        // onError (skips ones that already handle it, so no double toasts).
+        mutationCache: new MutationCache({
+          onError: (error, _vars, _ctx, mutation) => {
+            if (mutation.options.onError) return;
+            notify.error(getErrorMessage(error, globalMutationErrorFallback()));
+          },
+        }),
         defaultOptions: {
           queries: {
             staleTime: 30_000,

web/dashboard/src/components/reservations/reservations-screen.tsx

@@ -234,6 +234,7 @@ export function ReservationsScreen() {
                         <Can permission="EditReservation">
                           <Button
                             size="sm"
+                            disabled={updateStatus.isPending}
                             onClick={() => updateStatus.mutate({ id: r.id, status: "Confirmed" })}
                           >
                             {t("confirm")}
@@ -243,6 +244,7 @@ export function ReservationsScreen() {
                           <Button
                             size="sm"
                             variant="outline"
+                            disabled={updateStatus.isPending}
                             onClick={() => updateStatus.mutate({ id: r.id, status: "Cancelled" })}
                           >
                             {t("cancel")}
@@ -260,6 +262,7 @@ export function ReservationsScreen() {
                         <Button
                           size="sm"
                           variant="outline"
+                          disabled={updateStatus.isPending}
                           onClick={() => updateStatus.mutate({ id: r.id, status: "Completed" })}
                         >
                           {t("markCompleted")}

web/dashboard/src/components/settings/settings-notifications-panel.tsx

@@ -186,7 +186,7 @@ export function SettingsNotificationsPanel() {
                 disabled={!prefs.desktopEnabled}
                 onClick={() => {
                   if (prefs.soundEnabled) playSound(prefs.soundId, prefs.volume);
-                  showDesktopNotification({ title: t("testTitle"), body: t("testBody") });
+                  showDesktopNotification({ title: t("testTitle"), body: t("testBody"), force: true });
                   notify.info(t("testToast"));
                 }}
               >

web/dashboard/src/lib/hooks/use-notifications-feed.ts

@@ -1,8 +1,7 @@
 "use client";
 
-import { useCallback, useEffect } from "react";
+import { useCallback } from "react";
 import { useQuery, useQueryClient } from "@tanstack/react-query";
-import * as signalR from "@microsoft/signalr";
 import { useRouter } from "@/i18n/routing";
 import {
   fetchNotifications,
@@ -10,23 +9,26 @@ import {
   type CafeNotification,
 } from "@/lib/api/notifications";
 import { useAuthStore } from "@/lib/stores/auth.store";
-import { notify } from "@/lib/notify";
 import { notificationDestinationFromStore } from "@/lib/notifications/notification-routes";
 
 type UseNotificationsFeedOptions = {
   unreadOnly?: boolean;
   limit?: number;
-  /** Show toast when a new guest order notification arrives (topbar). */
-  enableToasts?: boolean;
 };
 
 type OpenNotificationOptions = {
-  /** Navigate to KDS/tables after marking read (notifications page only). */
+  /** Navigate to the related page after marking read (notifications page only). */
   navigate?: boolean;
 };
 
+/**
+ * Notification list + read actions. The live SignalR connection is owned by
+ * useOrderAlerts (mounted once in the dashboard shell), which invalidates the
+ * ["notifications", cafeId] query on each incoming event — so this hook just
+ * reads the shared query (no second hub connection) and polls as a backstop.
+ */
 export function useNotificationsFeed(options: UseNotificationsFeedOptions = {}) {
-  const { unreadOnly = false, limit = 50, enableToasts = false } = options;
+  const { unreadOnly = false, limit = 50 } = options;
   const cafeId = useAuthStore((s) => s.user?.cafeId);
   const router = useRouter();
   const qc = useQueryClient();
@@ -45,37 +47,6 @@ export function useNotificationsFeed(options: UseNotificationsFeedOptions = {})
     void qc.invalidateQueries({ queryKey: ["notifications", cafeId] });
   }, [qc, cafeId]);
 
-  useEffect(() => {
-    if (!cafeId) return;
-    const token = localStorage.getItem("meezi_access_token");
-    const baseUrl = process.env.NEXT_PUBLIC_API_URL ?? "https://localhost:7208";
-    const connection = new signalR.HubConnectionBuilder()
-      .withUrl(`${baseUrl}/hubs/kds`, { accessTokenFactory: () => token ?? "" })
-      .withAutomaticReconnect()
-      .build();
-
-    connection
-      .start()
-      .then(() => connection.invoke("JoinCafe", cafeId))
-      .catch(() => undefined);
-
-    connection.on("NotificationReceived", (n: CafeNotification) => {
-      refresh();
-      if (enableToasts) {
-        if (n.type === "table_call_waiter") {
-          notify.warning(n.title, { description: n.body ?? undefined });
-        } else if (n.type === "guest_order_new") {
-          notify.info(n.title, { description: n.body ?? undefined });
-        }
-      }
-    });
-    connection.on("OrderCreated", refresh);
-
-    return () => {
-      void connection.stop();
-    };
-  }, [cafeId, refresh, enableToasts]);
-
   const openNotification = useCallback(
     async (n: CafeNotification, opts: OpenNotificationOptions = {}) => {
       if (!cafeId) return;

web/dashboard/src/lib/notifications/use-desktop-notifications.ts

@@ -37,11 +37,13 @@ export function showDesktopNotification(opts: {
   tag?: string;
   /** In-app path to open when the popup is clicked. */
   path?: string | null;
+  /** Bypass the "only when tab hidden" rule — for the settings test button. */
+  force?: boolean;
 }): void {
   if (!notificationsSupported()) return;
   if (!useNotifPrefs.getState().desktopEnabled) return;
   if (Notification.permission !== "granted") return;
-  if (typeof document !== "undefined" && document.visibilityState === "visible") return;
+  if (!opts.force && typeof document !== "undefined" && document.visibilityState === "visible") return;
   try {
     const n = new Notification(opts.title, {
       body: opts.body,