Merge main_v2 mobile UI into production, restore mobile bottom tab bar

Merges main_v2 a110741 (mobile UI optimizations) into production and
reinstates the mobile bottom navigation that f0e4243 had removed.

Conflicts in DashboardPage, QuoteCard and InventoryPage resolved in
favour of main_v2's mobile-first markup, keeping production's newer
design system (Button variant="primary" on InventoryPage).

f0e4243's removal was reverted in effect: MobileTabBar is restored and
remounted in App.tsx, and PageLayout regains max-md:pb-24 clearance so
content is not hidden behind the fixed bar.

frontend/src/pages/Dashboard/DashboardPage.tsx

@@ -22,7 +22,6 @@ import { EditModal } from "./EditModal";
 
 const EMPTY_FILTERS: Filters = { category: "", supplier: "", status: "", search: "" };
 
-// صفحه‌ی اصلی دفتر پیشنهادهای خرید
 export function DashboardPage() {
   useStoreData();
 
@@ -73,20 +72,16 @@ export function DashboardPage() {
   const supplierOptions = useMemo(() => suppliers.map((s) => ({ id: s.id, name: s.name })), [suppliers]);
 
   return (
-    <div className="min-h-screen">
+    <div className="min-h-screen pb-20 md:pb-6">
       <Header
         title="دفتر پیشنهادهای خرید"
         brand
         menu={<AppSwitcherMenu activeModule="procurement" />}
         actions={
-          <div className="flex items-center gap-2">
-            {/* دکمه تأمین‌کننده‌ها */}
-            <Link
-              to="/suppliers"
-              className="inline-flex items-center gap-1.5 px-3.5 py-2 rounded-xl border border-gray-200 dark:border-zinc-700 bg-white dark:bg-zinc-800 text-gray-700 dark:text-zinc-200 text-xs font-semibold hover:bg-gray-50 dark:hover:bg-zinc-700 shadow-2xs transition-all no-underline"
-            >
-              <Users className="h-4 w-4 text-gray-500 dark:text-zinc-400" />
-              <span>تأمین‌کننده‌ها</span>
+          <div className="hidden md:flex items-center gap-2">
+            <Link to="/suppliers" className="btn-line-file no-underline">
+              <Users className="h-3.5 w-3.5" />
+              تأمین‌کننده‌ها
             </Link>
 
             {/* دکمه پروژه‌ها */}
@@ -118,7 +113,8 @@ export function DashboardPage() {
           </div>
         }
       />
-      <PageLayout className="flex flex-col gap-4">
+
+      <PageLayout className="flex flex-col gap-3 px-3 md:px-6">
         <StatsBar
           total={stats.total}
           offered={stats.offered}
@@ -143,6 +139,15 @@ export function DashboardPage() {
         />
       </PageLayout>
 
+      {/* دکمه شناور اکشن (FAB) مخصوص نسخه موبایل */}
+      <Link
+        to="/wizard"
+        aria-label="افزودن پیشنهاد جدید"
+        className="md:hidden fixed bottom-20 left-4 z-40 flex h-14 w-14 items-center justify-center rounded-full bg-accent text-white shadow-xl shadow-accent/30 active:scale-95 transition-transform"
+      >
+        <Plus className="h-7 w-7" />
+      </Link>
+
       <AcceptModal quoteId={acceptId} onClose={() => setAcceptId(null)} />
       <EditModal quoteId={editId} onClose={() => setEditId(null)} />
     </div>