feat(tema): açık / koyu / sistem teması

- TemaSaglayici (next-themes) + alt bilgide TemaSecici
- globals.css: .dark bloğunda palet token'ları çevrilir; bileşenlere
  dark: sınıfı yazılmaz
- yüzeyler bg-white → bg-card, koyu haplar text-slate-50, SVG'lerde
  sabit renk yerine değişken
- DESIGN.md §2.3 + tasarim-denetim kuralları (yuzey-beyaz,
  koyu-hap-beyaz-yazi, dark-sinif), AGENTS.md karanlık mod bölümü
- docs: koyu tema denetimi raporu

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

src/features/odeme/components/paket-satinal.tsx

@@ -55,10 +55,10 @@ export function PaketSatinAl() {
   return (
     <Parallax
       strength={6}
-      className="mt-10 grid gap-6 sm:grid-cols-[1fr_auto]"
+      className="mt-10 grid grid-cols-[minmax(0,1fr)] gap-6 sm:grid-cols-[minmax(0,1fr)_auto]"
     >
       {/* Ana paket */}
-      <section className="rounded-2xl border-2 border-orange-500 bg-white p-8 shadow-sm">
+      <section className="rounded-2xl border-2 border-orange-500 bg-card p-8 shadow-sm">
         <div className="flex items-baseline justify-between">
           <h2 className="font-heading text-xl font-bold">
             Tercih Dönemi Paketi
@@ -88,7 +88,7 @@ export function PaketSatinAl() {
           alt="iyzico ile Öde — Mastercard, Visa, American Express ve Troy ile güvenli ödeme"
           width={429}
           height={32}
-          className="mx-auto mt-5 h-5 w-auto"
+          className="kt-acik-logo mx-auto mt-5 h-5 w-auto"
         />
         <p className="mt-3 text-center text-xs text-slate-500">
           iyzico güvenli ödeme · Kart bilgilerin bize hiç ulaşmaz ·{" "}
@@ -102,7 +102,7 @@ export function PaketSatinAl() {
       </section>
 
       {/* Top-up */}
-      <section className="flex h-fit flex-col rounded-2xl border border-slate-200 bg-white p-6 shadow-sm sm:w-56">
+      <section className="flex h-fit flex-col rounded-2xl border border-slate-200 bg-card p-6 shadow-sm sm:w-56">
         <div className="flex items-center gap-2">
           <Coins className="size-4 text-amber-500" aria-hidden />
           <h2 className="font-heading font-bold">Kredi bitti mi?</h2>
@@ -130,7 +130,7 @@ async function PaketCta() {
       <div className="space-y-2">
         <Button
           asChild
-          className="h-12 w-full cursor-pointer bg-orange-500 px-8 text-white transition-colors duration-200 hover:bg-orange-600"
+          className="h-auto min-h-12 w-full cursor-pointer bg-orange-500 px-6 py-2 text-center whitespace-normal text-white transition-colors duration-200 hover:bg-orange-600 sm:px-8"
         >
           <Link href={`/giris?callback=${encodeURIComponent("/paket")}`}>
             Giriş yap — ilk {ACIK_SATIR} tercihini ücretsiz gör