feat(shell): personalized sidebar + header with real user and company

- Layout split: (dashboard)/layout.tsx is now async server component that
  fetches active context and passes user/company to (dashboard)/dashboard-shell.tsx
  (client). Redirects to /onboarding if no tenant.
- AppSidebar:
  * Header shows 'İşletmem' + the active company name (companyName from
    tenant_settings), instead of mock 'ShadcnStore / Admin Dashboard'.
  * Nav rebuilt for our modules in Turkish: Genel bakış, Müşteriler,
    Hizmetler, Yazılımlarımız, Takvim, Görevler, Gelir/Gider, Faturalar,
    Çalışma alanı (with submenu), Profil, Plan.
  * Removed SidebarNotification (template promo widget).
  * Accepts user/company props (typed via ShellUser/ShellCompany).
- NavUser:
  * Real user name + email, no more 'ShadcnStore / store@example.com'.
  * Avatar shows initials from name in primary/10 tinted square.
  * Logout wired to signOutAction (server action) via useTransition.
  * Menu items localized (Profil, Plan & Faturalama, Bildirimler, Çıkış yap).
- SiteHeader:
  * Removed Blocks / Landing / GitHub external links (template demo links).
  * Shows company name with Building2 icon between sidebar trigger and
    search trigger.
  * Search trigger moved to right side next to ModeToggle.
- Dropped UpgradeToProButton from the shell (template promo).
- Deleted dead-code src/components/layouts/base-layout.tsx (unused alt
  layout that wasn't compatible with the new AppSidebar props).

src/components/nav-user.tsx

@@ -1,15 +1,15 @@
-"use client"
+"use client";
 
+import { useTransition } from "react";
 import {
+  BellDot,
+  CircleUser,
   CreditCard,
   EllipsisVertical,
   LogOut,
-  BellDot,
-  CircleUser,
-} from "lucide-react"
-import Link from "next/link"
+} from "lucide-react";
+import Link from "next/link";
 
-import { Logo } from "@/components/logo"
 import {
   DropdownMenu,
   DropdownMenuContent,
@@ -18,24 +18,33 @@ import {
   DropdownMenuLabel,
   DropdownMenuSeparator,
   DropdownMenuTrigger,
-} from "@/components/ui/dropdown-menu"
+} from "@/components/ui/dropdown-menu";
 import {
   SidebarMenu,
   SidebarMenuButton,
   SidebarMenuItem,
   useSidebar,
-} from "@/components/ui/sidebar"
+} from "@/components/ui/sidebar";
+import { signOutAction } from "@/lib/appwrite/auth-actions";
+
+function initials(name: string) {
+  const parts = name.trim().split(/\s+/).slice(0, 2);
+  return parts.map((p) => p[0]?.toUpperCase() ?? "").join("") || "?";
+}
 
 export function NavUser({
   user,
 }: {
-  user: {
-    name: string
-    email: string
-    avatar: string
-  }
+  user: { name: string; email: string };
 }) {
-  const { isMobile } = useSidebar()
+  const { isMobile } = useSidebar();
+  const [isPending, startTransition] = useTransition();
+
+  const handleSignOut = () => {
+    startTransition(async () => {
+      await signOutAction();
+    });
+  };
 
   return (
     <SidebarMenu>
@@ -46,14 +55,12 @@ export function NavUser({
               size="lg"
               className="data-[state=open]:bg-sidebar-accent data-[state=open]:text-sidebar-accent-foreground cursor-pointer"
             >
-              <div className="flex h-8 w-8 items-center justify-center rounded-lg">
-                < Logo size={28} />
+              <div className="bg-primary/10 text-primary flex size-8 items-center justify-center rounded-lg text-sm font-medium">
+                {initials(user.name)}
               </div>
               <div className="grid flex-1 text-left text-sm leading-tight">
                 <span className="truncate font-medium">{user.name}</span>
-                <span className="text-muted-foreground truncate text-xs">
-                  {user.email}
-                </span>
+                <span className="text-muted-foreground truncate text-xs">{user.email}</span>
               </div>
               <EllipsisVertical className="ml-auto size-4" />
             </SidebarMenuButton>
@@ -66,14 +73,12 @@ export function NavUser({
           >
             <DropdownMenuLabel className="p-0 font-normal">
               <div className="flex items-center gap-2 px-1 py-1.5 text-left text-sm">
-                <div className="h-8 w-8 rounded-lg">
-                  < Logo size={28} />
+                <div className="bg-primary/10 text-primary flex size-8 items-center justify-center rounded-lg text-sm font-medium">
+                  {initials(user.name)}
                 </div>
                 <div className="grid flex-1 text-left text-sm leading-tight">
                   <span className="truncate font-medium">{user.name}</span>
-                  <span className="text-muted-foreground truncate text-xs">
-                    {user.email}
-                  </span>
+                  <span className="text-muted-foreground truncate text-xs">{user.email}</span>
                 </div>
               </div>
             </DropdownMenuLabel>
@@ -82,32 +87,34 @@ export function NavUser({
               <DropdownMenuItem asChild className="cursor-pointer">
                 <Link href="/settings/account">
                   <CircleUser />
-                  Account
+                  Profil
                 </Link>
               </DropdownMenuItem>
               <DropdownMenuItem asChild className="cursor-pointer">
                 <Link href="/settings/billing">
                   <CreditCard />
-                  Billing
+                  Plan & Faturalama
                 </Link>
               </DropdownMenuItem>
               <DropdownMenuItem asChild className="cursor-pointer">
                 <Link href="/settings/notifications">
                   <BellDot />
-                  Notifications
+                  Bildirimler
                 </Link>
               </DropdownMenuItem>
             </DropdownMenuGroup>
             <DropdownMenuSeparator />
-            <DropdownMenuItem asChild className="cursor-pointer">
-              <Link href="/sign-in">
-                <LogOut />
-                Log out
-              </Link>
+            <DropdownMenuItem
+              onClick={handleSignOut}
+              disabled={isPending}
+              className="cursor-pointer"
+            >
+              <LogOut />
+              {isPending ? "Çıkış yapılıyor..." : "Çıkış yap"}
             </DropdownMenuItem>
           </DropdownMenuContent>
         </DropdownMenu>
       </SidebarMenuItem>
     </SidebarMenu>
-  )
+  );
 }