feat: KVKK/GDPR uyumlu cookie consent + Google Consent Mode v2

Yeni component'ler:
- CookieBanner (sağ alt banner + tam ekran ayarlar modal)
  - 'Tümünü kabul', 'Tümünü reddet', 'Ayarları yönet'
  - 4 kategori toggle: Zorunlu / Analitik / Reklam / Tercih
  - Zorunlu kategori her zaman açık (KVKK)
  - localStorage + cookie persistence (12 ay TTL)
  - Versionlı (CONSENT_VERSION=1) — şema değişince yeniden sorma
  - window.openCookieSettings() global helper (footer/policy sayfasından çağrılabilir)
- ConsentInit (Google Consent Mode v2 default deny)
  - beforeInteractive Script ile gtag default deny yüklenir
  - User onayladığında banner gtag('consent','update', ...) çağırır
  - seo_settings.gtm_id doluysa GTM injection (asenkron)
- CookieSettingsButton (politika sayfasında 'ayarları değiştir')

Yeni sayfa:
- /cerez-politikasi — KVKK uyumlu çerez politikası metni
  - 4 kategori detaylı açıklama + örnek çerez isimleri
  - KVKK Madde 11 kapsamındaki kullanıcı hakları
  - İletişim bilgileri site_settings'ten

Layout entegrasyonu:
- app/layout.tsx — ConsentInit head'e, CookieBanner body sonuna
- Footer'a 'Çerez Politikası' linki

Consent flag mapping (Consent Mode v2):
- Zorunlu → functionality_storage + security_storage (her zaman granted)
- Analitik → analytics_storage
- Reklam → ad_storage + ad_user_data + ad_personalization
- Tercih → personalization_storage

Önemli: Default state 'denied' — kullanıcı seçim yapmadan
hiçbir analytics/ads çerezi tetiklenmez. Google Ads Consent Mode v2 uyumlu.

31 route, public sayfalar static (1m revalidate).

components/consent-init.tsx

@@ -0,0 +1,52 @@
+import Script from "next/script";
+
+/**
+ * Google Consent Mode v2 — defaults set to "denied" before any tag loads.
+ * After the user makes a choice, CookieBanner calls gtag('consent','update', ...).
+ *
+ * GTM/GA inject sadece site_settings.gtm_id doluysa yapılır.
+ */
+export function ConsentInit({ gtmId }: { gtmId?: string | null }) {
+  return (
+    <>
+      <Script id="consent-default" strategy="beforeInteractive">
+        {`
+          window.dataLayer = window.dataLayer || [];
+          function gtag(){dataLayer.push(arguments);}
+          window.gtag = gtag;
+          gtag('consent', 'default', {
+            ad_storage: 'denied',
+            ad_user_data: 'denied',
+            ad_personalization: 'denied',
+            analytics_storage: 'denied',
+            functionality_storage: 'granted',
+            personalization_storage: 'denied',
+            security_storage: 'granted',
+            wait_for_update: 500,
+          });
+        `}
+      </Script>
+
+      {gtmId && (
+        <>
+          <Script id="gtm-script" strategy="afterInteractive">
+            {`
+              (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start': new Date().getTime(),event:'gtm.js'});
+              var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';
+              j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
+              })(window,document,'script','dataLayer','${gtmId}');
+            `}
+          </Script>
+          <noscript>
+            <iframe
+              src={`https://www.googletagmanager.com/ns.html?id=${gtmId}`}
+              height="0"
+              width="0"
+              style={{ display: "none", visibility: "hidden" }}
+            />
+          </noscript>
+        </>
+      )}
+    </>
+  );
+}

components/cookie-banner.tsx

@@ -0,0 +1,321 @@
+"use client";
+
+import { useEffect, useState } from "react";
+import Link from "next/link";
+import { Cookie, Settings2, X } from "lucide-react";
+import {
+  CONSENT_COOKIE_NAME,
+  CONSENT_STORAGE_KEY,
+  CONSENT_TTL_DAYS,
+  CONSENT_VERSION,
+  type ConsentState,
+} from "@/lib/consent-types";
+
+type Mode = "hidden" | "banner" | "settings";
+
+declare global {
+  interface Window {
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    dataLayer?: any[];
+    gtag?: (...args: unknown[]) => void;
+    openCookieSettings?: () => void;
+  }
+}
+
+function setCookie(value: string) {
+  const expires = new Date();
+  expires.setDate(expires.getDate() + CONSENT_TTL_DAYS);
+  document.cookie = `${CONSENT_COOKIE_NAME}=${encodeURIComponent(value)}; expires=${expires.toUTCString()}; path=/; SameSite=Lax`;
+}
+
+function loadConsent(): ConsentState | null {
+  try {
+    const raw = localStorage.getItem(CONSENT_STORAGE_KEY);
+    if (!raw) return null;
+    const parsed = JSON.parse(raw) as ConsentState;
+    if (parsed.version !== CONSENT_VERSION) return null;
+    return parsed;
+  } catch {
+    return null;
+  }
+}
+
+function saveConsent(state: ConsentState) {
+  localStorage.setItem(CONSENT_STORAGE_KEY, JSON.stringify(state));
+  setCookie(JSON.stringify({ a: state.analytics, m: state.marketing, p: state.preferences }));
+
+  // Google Consent Mode v2 update
+  if (typeof window !== "undefined" && window.gtag) {
+    window.gtag("consent", "update", {
+      ad_storage: state.marketing ? "granted" : "denied",
+      ad_user_data: state.marketing ? "granted" : "denied",
+      ad_personalization: state.marketing ? "granted" : "denied",
+      analytics_storage: state.analytics ? "granted" : "denied",
+      functionality_storage: "granted",
+      personalization_storage: state.preferences ? "granted" : "denied",
+      security_storage: "granted",
+    });
+  }
+
+  window.dispatchEvent(new CustomEvent("kovak:consent-updated", { detail: state }));
+}
+
+export function CookieBanner() {
+  const [mode, setMode] = useState<Mode>("hidden");
+  const [analytics, setAnalytics] = useState(false);
+  const [marketing, setMarketing] = useState(false);
+  const [preferences, setPreferences] = useState(false);
+
+  useEffect(() => {
+    const existing = loadConsent();
+    if (existing) {
+      setAnalytics(existing.analytics);
+      setMarketing(existing.marketing);
+      setPreferences(existing.preferences);
+      setMode("hidden");
+    } else {
+      // Tarayıcı yüklendikten sonra göster, FCP'yi etkilememek için kısa gecikme
+      const t = setTimeout(() => setMode("banner"), 800);
+      return () => clearTimeout(t);
+    }
+  }, []);
+
+  useEffect(() => {
+    window.openCookieSettings = () => setMode("settings");
+    return () => {
+      delete window.openCookieSettings;
+    };
+  }, []);
+
+  const acceptAll = () => {
+    saveConsent({
+      necessary: true,
+      analytics: true,
+      marketing: true,
+      preferences: true,
+      timestamp: Date.now(),
+      version: CONSENT_VERSION,
+    });
+    setAnalytics(true);
+    setMarketing(true);
+    setPreferences(true);
+    setMode("hidden");
+  };
+
+  const rejectAll = () => {
+    saveConsent({
+      necessary: true,
+      analytics: false,
+      marketing: false,
+      preferences: false,
+      timestamp: Date.now(),
+      version: CONSENT_VERSION,
+    });
+    setAnalytics(false);
+    setMarketing(false);
+    setPreferences(false);
+    setMode("hidden");
+  };
+
+  const saveSelection = () => {
+    saveConsent({
+      necessary: true,
+      analytics,
+      marketing,
+      preferences,
+      timestamp: Date.now(),
+      version: CONSENT_VERSION,
+    });
+    setMode("hidden");
+  };
+
+  if (mode === "hidden") return null;
+
+  return (
+    <>
+      {/* Banner */}
+      {mode === "banner" && (
+        <div className="fixed inset-x-3 bottom-3 z-50 sm:inset-x-auto sm:bottom-5 sm:left-5 sm:right-5 md:max-w-2xl">
+          <div className="rounded-2xl border border-[var(--border)] bg-white p-5 shadow-2xl shadow-[var(--navy)]/15 sm:p-6">
+            <div className="flex items-start gap-3">
+              <div className="hidden size-10 shrink-0 items-center justify-center rounded-xl bg-[var(--navy-50)] text-[var(--navy)] sm:flex">
+                <Cookie className="size-5" />
+              </div>
+              <div className="flex-1">
+                <h3 className="text-sm font-semibold text-[var(--navy)]">
+                  Çerez tercihiniz
+                </h3>
+                <p className="mt-1 text-xs leading-relaxed text-[var(--muted)]">
+                  Web sitemizde deneyiminizi geliştirmek, trafiği analiz etmek ve
+                  reklam performansını ölçmek için çerezler kullanıyoruz.{" "}
+                  <Link
+                    href="/cerez-politikasi"
+                    className="underline hover:text-[var(--navy)]"
+                  >
+                    Çerez Politikası
+                  </Link>
+                </p>
+
+                <div className="mt-4 flex flex-wrap gap-2">
+                  <button
+                    type="button"
+                    onClick={acceptAll}
+                    className="rounded-full bg-[var(--navy)] px-4 py-2 text-xs font-medium text-white transition hover:bg-[var(--navy-700)]"
+                  >
+                    Tümünü kabul et
+                  </button>
+                  <button
+                    type="button"
+                    onClick={rejectAll}
+                    className="rounded-full border border-[var(--border)] bg-white px-4 py-2 text-xs font-medium text-[var(--navy)] transition hover:bg-[var(--navy-50)]"
+                  >
+                    Tümünü reddet
+                  </button>
+                  <button
+                    type="button"
+                    onClick={() => setMode("settings")}
+                    className="inline-flex items-center gap-1.5 rounded-full border border-[var(--border)] bg-white px-4 py-2 text-xs font-medium text-[var(--muted)] transition hover:text-[var(--navy)]"
+                  >
+                    <Settings2 className="size-3.5" />
+                    Ayarları yönet
+                  </button>
+                </div>
+              </div>
+            </div>
+          </div>
+        </div>
+      )}
+
+      {/* Settings Modal */}
+      {mode === "settings" && (
+        <div
+          className="fixed inset-0 z-50 flex items-end justify-center bg-black/60 p-4 sm:items-center"
+          onClick={() => setMode("banner")}
+        >
+          <div
+            className="w-full max-w-lg rounded-2xl bg-white shadow-2xl"
+            onClick={(e) => e.stopPropagation()}
+          >
+            <div className="flex items-start justify-between border-b border-[var(--border)] p-6">
+              <div>
+                <h3 className="text-lg font-semibold text-[var(--navy)]">
+                  Çerez ayarları
+                </h3>
+                <p className="mt-1 text-xs text-[var(--muted)]">
+                  Hangi çerez türlerine izin verdiğinizi seçin.
+                </p>
+              </div>
+              <button
+                type="button"
+                aria-label="Kapat"
+                onClick={() => setMode("banner")}
+                className="rounded-md p-1 text-[var(--muted)] hover:bg-[var(--navy-50)] hover:text-[var(--navy)]"
+              >
+                <X className="size-5" />
+              </button>
+            </div>
+
+            <div className="max-h-[60vh] space-y-4 overflow-y-auto p-6">
+              <CategoryRow
+                title="Zorunlu çerezler"
+                description="Site temel işlevleri için gerekli. Oturum, güvenlik, form gönderimi. Devre dışı bırakılamaz."
+                checked
+                disabled
+              />
+              <CategoryRow
+                title="Analitik çerezler"
+                description="Ziyaretçi sayısı, sayfa görüntüleme, trafik kaynağı gibi anonim istatistikler. Google Analytics."
+                checked={analytics}
+                onChange={setAnalytics}
+              />
+              <CategoryRow
+                title="Reklam çerezleri"
+                description="Sizinle ilgili olabilecek reklamların gösterilmesi ve reklam performansının ölçülmesi. Google Ads, Meta Pixel."
+                checked={marketing}
+                onChange={setMarketing}
+              />
+              <CategoryRow
+                title="Tercih çerezleri"
+                description="Dil, bölge, görüntüleme tercihlerinizi hatırlamak için."
+                checked={preferences}
+                onChange={setPreferences}
+              />
+            </div>
+
+            <div className="flex flex-wrap items-center justify-end gap-2 border-t border-[var(--border)] bg-[var(--navy-50)]/40 p-4">
+              <button
+                type="button"
+                onClick={rejectAll}
+                className="rounded-full border border-[var(--border)] bg-white px-4 py-2 text-xs font-medium text-[var(--muted)] hover:text-[var(--navy)]"
+              >
+                Tümünü reddet
+              </button>
+              <button
+                type="button"
+                onClick={saveSelection}
+                className="rounded-full border border-[var(--navy)] bg-white px-4 py-2 text-xs font-medium text-[var(--navy)] hover:bg-[var(--navy-50)]"
+              >
+                Seçimi kaydet
+              </button>
+              <button
+                type="button"
+                onClick={acceptAll}
+                className="rounded-full bg-[var(--navy)] px-4 py-2 text-xs font-medium text-white hover:bg-[var(--navy-700)]"
+              >
+                Tümünü kabul et
+              </button>
+            </div>
+          </div>
+        </div>
+      )}
+    </>
+  );
+}
+
+function CategoryRow({
+  title,
+  description,
+  checked,
+  disabled,
+  onChange,
+}: {
+  title: string;
+  description: string;
+  checked: boolean;
+  disabled?: boolean;
+  onChange?: (v: boolean) => void;
+}) {
+  return (
+    <div className="rounded-xl border border-[var(--border)] bg-white p-4">
+      <div className="flex items-start justify-between gap-4">
+        <div>
+          <p className="text-sm font-semibold text-[var(--navy)]">{title}</p>
+          <p className="mt-1 text-xs leading-relaxed text-[var(--muted)]">
+            {description}
+          </p>
+        </div>
+        <label className="relative inline-flex shrink-0 cursor-pointer items-center">
+          <input
+            type="checkbox"
+            checked={checked}
+            disabled={disabled}
+            onChange={(e) => onChange?.(e.target.checked)}
+            className="peer sr-only"
+          />
+          <div
+            className={`h-6 w-11 rounded-full transition ${
+              disabled
+                ? "bg-[var(--sky)]/60"
+                : "bg-[var(--border)] peer-checked:bg-[var(--navy)]"
+            }`}
+          />
+          <div
+            className={`absolute left-0.5 top-0.5 size-5 rounded-full bg-white shadow transition ${
+              checked ? "translate-x-5" : ""
+            }`}
+          />
+        </label>
+      </div>
+    </div>
+  );
+}

components/cookie-settings-button.tsx

@@ -0,0 +1,16 @@
+"use client";
+
+import { Settings2 } from "lucide-react";
+
+export function CookieSettingsButton() {
+  return (
+    <button
+      type="button"
+      onClick={() => window.openCookieSettings?.()}
+      className="inline-flex items-center gap-1.5 rounded-full bg-[var(--navy)] px-4 py-2 text-xs font-medium text-white transition hover:bg-[var(--navy-700)]"
+    >
+      <Settings2 className="size-3.5" />
+      Çerez ayarlarını değiştir
+    </button>
+  );
+}

components/footer.tsx

@@ -112,7 +112,13 @@ export async function Footer() {
           <p>
             © {new Date().getFullYear()} {siteConfig.name}. Tüm hakları saklıdır.
           </p>
-          <p>Kocaeli, Türkiye</p>
+          <div className="flex flex-wrap items-center gap-3">
+            <Link href="/cerez-politikasi" className="hover:text-white">
+              Çerez Politikası
+            </Link>
+            <span>•</span>
+            <p>Kocaeli, Türkiye</p>
+          </div>
         </div>
       </div>
     </footer>