♻️ refactor(admin): restructure admin layout

- move sidebar below full-width sticky header
- wrap sidebar and content in flex row for desktop
- keep header visible above content at all breakpoints

src/GreenHome.Web/src/app/admin/AdminLayout.tsx

@@ -70,18 +70,9 @@ export default function AdminLayout() {
         })
 
     return (
-        <div className="min-h-screen bg-[#fafafa] flex flex-col md:flex-row">
+        <div className="min-h-screen bg-[#fafafa] flex flex-col">
-            {/* Desktop sidebar (right side in RTL) */}
+            {/* Sticky header — full width, above everything (merges the old mobile header) */}
-            <aside className="hidden md:flex flex-col w-60 shrink-0 border-l border-gray-200 bg-white p-4 sticky top-14 h-[calc(100vh-3.5rem)]">
+            <div className="sticky top-0 z-20 w-full">
-                <div className="px-3 py-4 mb-2 border-b border-gray-100">
-                    <h1 className="text-base font-bold text-gray-900">پنل مدیریت</h1>
-                    <p className="text-xs text-gray-400 mt-0.5">گ린‌هوم</p>
-                </div>
-                <nav className="flex-1 flex flex-col gap-1">{navLinks()}</nav>
-            </aside>
-
-            {/* Sticky header (all breakpoints, merges the old mobile header) */}
-            <div className="sticky top-0 z-20 w-full md:flex-1">
                 <header className="bg-white border-b border-gray-200">
                     <div className="h-14 flex items-center justify-between px-4 md:px-6">
                         <div className="flex items-center gap-2 min-w-0">
@@ -111,6 +102,17 @@ export default function AdminLayout() {
                 </header>
             </div>
 
+            {/* Below the header: sidebar (desktop) + content */}
+            <div className="flex flex-1 md:flex-row">
+                {/* Desktop sidebar (right side in RTL) */}
+                <aside className="hidden md:flex flex-col w-60 shrink-0 border-l border-gray-200 bg-white p-4 sticky top-14 h-[calc(100vh-3.5rem)]">
+                    <div className="px-3 py-4 mb-2 border-b border-gray-100">
+                        <h1 className="text-base font-bold text-gray-900">پنل مدیریت</h1>
+                        <p className="text-xs text-gray-400 mt-0.5">گ린‌هوم</p>
+                    </div>
+                    <nav className="flex-1 flex flex-col gap-1">{navLinks()}</nav>
+                </aside>
+
                 {/* Page content */}
                 <main className="flex-1 p-4 md:p-6">
                     <div className="max-w-5xl mx-auto">
@@ -118,5 +120,6 @@ export default function AdminLayout() {
                     </div>
                 </main>
             </div>
+        </div>
     )
 }