feat: SEO altyapısı + admin editör/favicon/menü düzeltmeleri

Admin & site:
- @tailwindcss/typography ekle → editör ve yayın içeriği prose stilleriyle düzgün render
- Favicon: logo.png'den kare app/icon.png + apple-icon.png, varsayılan favicon.ico kaldırıldı
- SEO keyword: seo_settings.default_keywords + seo_pages.keywords + buildMetadata birleştirme
- Menü düzeni admin'den yönetilebilir (site_settings.nav_items, /admin/menu, header & mobile-menu refactor)

SEO:
- app/sitemap.ts (statik + blog/hizmet/çözüm/proje/sektör dinamik)
- app/robots.ts (sitemap ref + /admin,/api disallow)
- app/llms.txt/route.ts (AI/LLM rehberi)
- BlogPosting/Service/FAQ/Article JSON-LD wire (json-ld bileşenleri bağlandı)
- buildMetadata: blog/proje OG görseli + type article + keywords birleştirme düzeltmesi
- blog tags → keyword

components/mobile-menu.tsx

@@ -5,22 +5,17 @@ import { createPortal } from "react-dom";
 import Link from "next/link";
 import { usePathname } from "next/navigation";
 import { Menu, X, ChevronDown, Phone, ArrowRight } from "lucide-react";
+import type { NavItem } from "@/lib/nav";
 
 type NavService = { slug: string; title: string };
 
-const LINKS = [
-  { href: "/cozumler", label: "Çözümler" },
-  { href: "/projeler", label: "Projeler" },
-  { href: "/blog", label: "Blog" },
-  { href: "/hakkimizda", label: "Hakkımızda" },
-  { href: "/iletisim", label: "İletişim" },
-];
-
 export function MobileMenu({
+  navItems,
   services,
   phone,
   phoneRaw,
 }: {
+  navItems: NavItem[];
   services: NavService[];
   phone: string;
   phoneRaw: string;
@@ -84,58 +79,57 @@ export function MobileMenu({
           </button>
         </div>
 
-        {/* Linkler */}
+        {/* Linkler — sıra admin'den yönetilir */}
         <nav className="flex-1 overflow-y-auto px-3 py-4">
-          <Link
-            href="/"
-            className="block rounded-xl px-4 py-3 text-base font-medium text-gray-800 transition-colors hover:bg-blue-50 hover:text-[var(--navy)]"
-          >
-            Anasayfa
-          </Link>
-
-          {/* Hizmetler — açılır */}
-          <button
-            type="button"
-            onClick={() => setServicesOpen((v) => !v)}
-            aria-expanded={servicesOpen}
-            className="flex w-full items-center justify-between rounded-xl px-4 py-3 text-base font-medium text-gray-800 transition-colors hover:bg-blue-50 hover:text-[var(--navy)]"
-          >
-            Hizmetler
-            <ChevronDown
-              className={`size-4 transition-transform duration-200 ${
-                servicesOpen ? "rotate-180" : ""
-              }`}
-            />
-          </button>
-          {servicesOpen && (
-            <div className="mb-1 ml-3 border-l border-gray-100 pl-3">
-              {services.map((s) => (
+          {navItems
+            .filter((item) => item.visible)
+            .map((item) =>
+              item.mega ? (
+                <div key={item.key}>
+                  {/* Hizmetler — açılır */}
+                  <button
+                    type="button"
+                    onClick={() => setServicesOpen((v) => !v)}
+                    aria-expanded={servicesOpen}
+                    className="flex w-full items-center justify-between rounded-xl px-4 py-3 text-base font-medium text-gray-800 transition-colors hover:bg-blue-50 hover:text-[var(--navy)]"
+                  >
+                    {item.label}
+                    <ChevronDown
+                      className={`size-4 transition-transform duration-200 ${
+                        servicesOpen ? "rotate-180" : ""
+                      }`}
+                    />
+                  </button>
+                  {servicesOpen && (
+                    <div className="mb-1 ml-3 border-l border-gray-100 pl-3">
+                      {services.map((s) => (
+                        <Link
+                          key={s.slug}
+                          href={`/hizmetler/${s.slug}`}
+                          className="block rounded-lg px-3 py-2 text-sm text-gray-600 transition-colors hover:bg-blue-50 hover:text-[var(--navy)]"
+                        >
+                          {s.title}
+                        </Link>
+                      ))}
+                      <Link
+                        href="/hizmetler"
+                        className="block rounded-lg px-3 py-2 text-sm font-semibold text-[var(--sky-600)] hover:text-[var(--navy)]"
+                      >
+                        Tüm hizmetleri gör →
+                      </Link>
+                    </div>
+                  )}
+                </div>
+              ) : (
                 <Link
-                  key={s.slug}
-                  href={`/hizmetler/${s.slug}`}
-                  className="block rounded-lg px-3 py-2 text-sm text-gray-600 transition-colors hover:bg-blue-50 hover:text-[var(--navy)]"
+                  key={item.key}
+                  href={item.href}
+                  className="block rounded-xl px-4 py-3 text-base font-medium text-gray-800 transition-colors hover:bg-blue-50 hover:text-[var(--navy)]"
                 >
-                  {s.title}
+                  {item.label}
                 </Link>
-              ))}
-              <Link
-                href="/hizmetler"
-                className="block rounded-lg px-3 py-2 text-sm font-semibold text-[var(--sky-600)] hover:text-[var(--navy)]"
-              >
-                Tüm hizmetleri gör →
-              </Link>
-            </div>
-          )}
-
-          {LINKS.map((l) => (
-            <Link
-              key={l.href}
-              href={l.href}
-              className="block rounded-xl px-4 py-3 text-base font-medium text-gray-800 transition-colors hover:bg-blue-50 hover:text-[var(--navy)]"
-            >
-              {l.label}
-            </Link>
-          ))}
+              ),
+            )}
         </nav>
 
         {/* Alt CTA */}