feat: admin paneli + blog + testimonials + SEO yöneticisi

Backend altyapısı:
- 4 yeni Appwrite tablosu: blog_posts, testimonials, seo_pages, seo_settings
- Appwrite Storage bucket: kovak-yazilim-media (görsel yüklemeleri)
- Appwrite Auth ile session cookie tabanlı koruma

Admin paneli (/admin):
- Login akışı (email/password) + protected layout
- Dashboard: sayım kartları + hızlı aksiyonlar
- Blog CRUD: markdown content, kapak görseli, draft/published, SEO alanları
- Services CRUD: lucide ikon seçici
- Projects CRUD: teknoloji etiketleri, live URL
- Testimonials CRUD: puanlama
- SEO yöneticisi: global ayarlar + sayfa bazlı override
- Mesaj inbox: status filtreleme + güncelleme
- Medya kütüphanesi: Appwrite Storage upload/delete

Public:
- /blog ve /blog/[slug] sayfaları (markdown render)
- Anasayfaya Testimonials bölümü
- Tüm public sayfalarda generateMetadata + seo_pages override
- Header'a Blog linki

Route yapısı:
- app/(site)/ — public site, Header/Footer ortak
- app/admin/login — auth dışı
- app/admin/(protected)/ — requireUser() korumalı

23 route üretiliyor, public static, admin dynamic.

app/admin/(protected)/blog/page.tsx

@@ -0,0 +1,103 @@
+import Link from "next/link";
+import { Plus, Edit, ExternalLink } from "lucide-react";
+import { PageHeader } from "@/components/admin/form";
+import { DeleteButton } from "@/components/admin/delete-button";
+import { listAllPosts } from "@/lib/data";
+import { deleteBlogPost } from "@/lib/admin-actions";
+
+export default async function BlogListPage() {
+  const posts = await listAllPosts();
+
+  return (
+    <div>
+      <PageHeader
+        title="Blog"
+        description="Yazılarınızı yönetin ve yayınlayın."
+        action={
+          <Link
+            href="/admin/blog/new"
+            className="inline-flex items-center gap-2 rounded-full bg-[var(--navy)] px-4 py-2 text-sm font-medium text-white transition hover:bg-[var(--navy-700)]"
+          >
+            <Plus className="size-4" /> Yeni yazı
+          </Link>
+        }
+      />
+
+      <div className="mt-6 overflow-hidden rounded-2xl border border-[var(--border)] bg-white">
+        <table className="w-full text-sm">
+          <thead className="bg-[var(--navy-50)] text-xs uppercase tracking-wider text-[var(--muted)]">
+            <tr>
+              <th className="px-4 py-3 text-left">Başlık</th>
+              <th className="px-4 py-3 text-left">Slug</th>
+              <th className="px-4 py-3 text-left">Durum</th>
+              <th className="px-4 py-3 text-left">Yayın</th>
+              <th className="px-4 py-3 text-right">İşlem</th>
+            </tr>
+          </thead>
+          <tbody>
+            {posts.length === 0 && (
+              <tr>
+                <td colSpan={5} className="px-4 py-12 text-center text-[var(--muted)]">
+                  Henüz yazı yok. İlk yazınızı oluşturun.
+                </td>
+              </tr>
+            )}
+            {posts.map((p) => (
+              <tr key={p.$id} className="border-t border-[var(--border)]">
+                <td className="px-4 py-3 font-medium text-[var(--navy)]">{p.title}</td>
+                <td className="px-4 py-3 text-[var(--muted)]">/{p.slug}</td>
+                <td className="px-4 py-3">
+                  <StatusBadge status={p.status} />
+                </td>
+                <td className="px-4 py-3 text-[var(--muted)]">
+                  {p.published_at
+                    ? new Date(p.published_at).toLocaleDateString("tr-TR")
+                    : "—"}
+                </td>
+                <td className="px-4 py-3">
+                  <div className="flex items-center justify-end gap-2">
+                    {p.status === "published" && (
+                      <Link
+                        href={`/blog/${p.slug}`}
+                        target="_blank"
+                        className="rounded-md border border-[var(--border)] p-1.5 text-[var(--muted)] hover:text-[var(--navy)]"
+                      >
+                        <ExternalLink className="size-3.5" />
+                      </Link>
+                    )}
+                    <Link
+                      href={`/admin/blog/${p.$id}/edit`}
+                      className="inline-flex items-center gap-1 rounded-md border border-[var(--border)] bg-white px-2.5 py-1.5 text-xs font-medium text-[var(--navy)] hover:bg-[var(--navy-50)]"
+                    >
+                      <Edit className="size-3.5" />
+                      Düzenle
+                    </Link>
+                    <form action={deleteBlogPost}>
+                      <input type="hidden" name="id" value={p.$id} />
+                      <DeleteButton />
+                    </form>
+                  </div>
+                </td>
+              </tr>
+            ))}
+          </tbody>
+        </table>
+      </div>
+    </div>
+  );
+}
+
+function StatusBadge({ status }: { status?: string | null }) {
+  const isPub = status === "published";
+  return (
+    <span
+      className={`inline-flex items-center rounded-full px-2 py-0.5 text-xs font-medium ${
+        isPub
+          ? "bg-green-100 text-green-800"
+          : "bg-amber-100 text-amber-800"
+      }`}
+    >
+      {isPub ? "Yayında" : "Taslak"}
+    </span>
+  );
+}