feat(dashboard): Next.js 16 merchant panel with offline POS and PWA

Complete merchant dashboard upgrade:

Next.js 16 compatibility:
- Fix params/searchParams typed as Promise<{}> throughout App Router
- Replace middleware.ts with proxy.ts (Next.js 16 convention)
- Remove unused @ts-expect-error directives caught by stricter TS
- Cast dynamic next-intl t() keys to fix TranslateArgs type errors

Offline POS:
- IndexedDB queue (meezi_pos_offline) for orders created while offline
- Zustand sync store tracking queueCount, isSyncing, isOnline
- useOfflineSync hook: auto-syncs on reconnect/visibility-change
- SyncStatusIndicator chip in topbar (amber=offline, blue=syncing)
- submitOrderToApi falls back to local order on network failure
- Local orders skip payment flow; sync on reconnect

PWA (installable):
- @ducanh2912/next-pwa with Workbox runtime caching rules
- Web App Manifest (manifest.ts) — RTL/Farsi, theme #0F6E56
- PWA icons: 192px, 512px, maskable 512px
- next.config.ts replaces next.config.mjs

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

web/dashboard/src/lib/sidebar-nav.ts

@@ -0,0 +1,134 @@
+import type { LucideIcon } from "lucide-react";
+import {
+  LayoutGrid,
+  UtensilsCrossed,
+  Users,
+  Ticket,
+  Package,
+  BookOpen,
+  UserCog,
+  BarChart3,
+  Calendar,
+  Star,
+  MessageSquare,
+  Receipt,
+  Settings,
+  ChefHat,
+  Bell,
+  ListOrdered,
+  Building2,
+  CreditCard,
+  Wallet,
+  Clock,
+  LifeBuoy,
+  Compass,
+} from "lucide-react";
+
+export type NavGroupId = "operations" | "menuSales" | "customers" | "finance" | "management";
+
+export type NavItemKey =
+  | "pos"
+  | "tables"
+  | "queue"
+  | "kds"
+  | "notifications"
+  | "reservations"
+  | "menu"
+  | "inventory"
+  | "coupons"
+  | "crm"
+  | "sms"
+  | "reviews"
+  | "discover"
+  | "reports"
+  | "expenses"
+  | "shifts"
+  | "taxes"
+  | "hr"
+  | "branches"
+  | "subscription"
+  | "support"
+  | "settings";
+
+export type NavItemDef = {
+  key: NavItemKey;
+  href: string;
+  icon: LucideIcon;
+};
+
+export type NavGroupDef = {
+  id: NavGroupId;
+  defaultOpen: boolean;
+  items: NavItemDef[];
+};
+
+export const NAV_GROUPS: NavGroupDef[] = [
+  {
+    id: "operations",
+    defaultOpen: true,
+    items: [
+      { key: "pos", href: "/pos", icon: LayoutGrid },
+      { key: "tables", href: "/tables", icon: UtensilsCrossed },
+      { key: "queue", href: "/queue", icon: ListOrdered },
+      { key: "kds", href: "/kds", icon: ChefHat },
+      { key: "notifications", href: "/notifications", icon: Bell },
+      { key: "reservations", href: "/reservations", icon: Calendar },
+    ],
+  },
+  {
+    id: "menuSales",
+    defaultOpen: true,
+    items: [
+      { key: "menu", href: "/menu", icon: BookOpen },
+      { key: "inventory", href: "/inventory", icon: Package },
+      { key: "coupons", href: "/coupons", icon: Ticket },
+    ],
+  },
+  {
+    id: "customers",
+    defaultOpen: true,
+    items: [
+      { key: "crm", href: "/crm", icon: Users },
+      { key: "sms", href: "/sms", icon: MessageSquare },
+      { key: "reviews", href: "/reviews", icon: Star },
+      { key: "discover", href: "/discover", icon: Compass },
+    ],
+  },
+  {
+    id: "finance",
+    defaultOpen: true,
+    items: [
+      { key: "reports", href: "/reports", icon: BarChart3 },
+      { key: "expenses", href: "/expenses", icon: Wallet },
+      { key: "shifts", href: "/shifts", icon: Clock },
+      { key: "taxes", href: "/taxes", icon: Receipt },
+    ],
+  },
+  {
+    id: "management",
+    defaultOpen: true,
+    items: [
+      { key: "hr", href: "/hr", icon: UserCog },
+      { key: "branches", href: "/branches", icon: Building2 },
+      { key: "subscription", href: "/subscription", icon: CreditCard },
+      { key: "settings", href: "/settings", icon: Settings },
+      { key: "support", href: "/support", icon: LifeBuoy },
+    ],
+  },
+];
+
+export const NAV_GROUPS_STORAGE_KEY = "meezi:nav-groups:v3";
+
+/** Branch-scoped staff only see daily operations. */
+export const BRANCH_ONLY_NAV_GROUP: NavGroupId = "operations";
+
+export function findNavGroupForPath(pathname: string): NavGroupId | null {
+  for (const group of NAV_GROUPS) {
+    for (const item of group.items) {
+      if (pathname === item.href || pathname.startsWith(`${item.href}/`)) {
+        return group.id;
+      }
+    }
+  }
+  return null;
+}