feat: implement DELETE /restaurants/:id endpoint and mobile UI danger zone for restaurant deletion

apps/mobile/src/app/account/index.tsx

@@ -81,6 +81,7 @@ export default function AccountScreen() {
   const [logoUrl, setLogoUrl] = useState<string | null>(null);
   const [slug, setSlug] = useState("");
   const [savingRest, setSavingRest] = useState(false);
+  const [deletingRestaurant, setDeletingRestaurant] = useState(false);
 
   // Theme state
   const [selectedTheme, setSelectedTheme] = useState("elegant");
@@ -319,6 +320,39 @@ export default function AccountScreen() {
     );
   }
 
+  async function handleDeleteRestaurant() {
+    if (!active) return;
+    Alert.alert(
+      "Restoranı Kalıcı Olarak Sil ⚠️",
+      `"${name}" restoranını ve bu restorana ait tüm menüleri, kategorileri, ürünleri ve özel alan adlarını kalıcı olarak silmek istediğinize emin misiniz?\n\nBu işlem geri alınamaz!`,
+      [
+        { text: "Vazgeç", style: "cancel" },
+        {
+          text: "Evet, Kalıcı Olarak Sil",
+          style: "destructive",
+          onPress: async () => {
+            setDeletingRestaurant(true);
+            Haptics.impactAsync(Haptics.ImpactFeedbackStyle.Heavy).catch(() => {});
+            try {
+              await api.delete(`/restaurants/${active.restaurantId}`);
+              await clearActiveRestaurant();
+              Haptics.notificationAsync(Haptics.NotificationFeedbackType.Success).catch(() => {});
+              Alert.alert("Silindi 🗑️", "Restoranınız başarıyla silindi.", [
+                {
+                  text: "Tamam",
+                  onPress: () => router.replace("/(onboarding)/restaurant"),
+                },
+              ]);
+            } catch (err) {
+              Alert.alert("Hata", err instanceof Error ? err.message : "Restoran silinemedi.");
+              setDeletingRestaurant(false);
+            }
+          },
+        },
+      ],
+    );
+  }
+
   if (loading) {
     return (
       <View style={{ flex: 1, backgroundColor: "#FAF8F5", alignItems: "center", justifyContent: "center" }}>
@@ -951,6 +985,51 @@ export default function AccountScreen() {
             </Text>
           </Pressable>
         </View>
+
+        {/* Danger Zone: Delete Restaurant */}
+        <View
+          style={{
+            backgroundColor: "#FEF2F2",
+            borderRadius: 20,
+            padding: 20,
+            borderWidth: 1,
+            borderColor: "#FEE2E2",
+            gap: 12,
+          }}
+        >
+          <View style={{ flexDirection: "row", alignItems: "center", gap: 8 }}>
+            <Ionicons name="warning-outline" size={20} color="#DC2626" />
+            <Text style={{ fontSize: 16, fontWeight: "800", color: "#991B1B" }}>
+              Tehlikeli Bölge
+            </Text>
+          </View>
+
+          <Text style={{ fontSize: 12, color: "#991B1B", lineHeight: 18 }}>
+            Restoranınızı sildiğinizde bu restorana bağlı tüm menüler, kategoriler, ürünler ve özel alan adı ayarları kalıcı olarak silinir.
+          </Text>
+
+          <Pressable
+            onPress={handleDeleteRestaurant}
+            disabled={deletingRestaurant}
+            style={({ pressed }) => ({
+              backgroundColor: "#DC2626",
+              borderRadius: 12,
+              paddingVertical: 14,
+              alignItems: "center",
+              justifyContent: "center",
+              opacity: pressed || deletingRestaurant ? 0.85 : 1,
+              marginTop: 4,
+            })}
+          >
+            {deletingRestaurant ? (
+              <ActivityIndicator size="small" color="#FFFFFF" />
+            ) : (
+              <Text style={{ color: "#FFFFFF", fontSize: 14, fontWeight: "800" }}>
+                Restoranı Kalıcı Olarak Sil
+              </Text>
+            )}
+          </Pressable>
+        </View>
       </ScrollView>
     </View>
   );