feat(mobile): language management UI in account settings

Restaurant owners can now enable/disable AI-translated menu languages
(EN/DE/AR/RU/FR) from the account screen, calling the new
/restaurants/:id/languages endpoints. Turkish stays as the fixed base
language; adding a language triggers a full AI translation pass, removing
one just hides it (translations are kept for a fast re-enable).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

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

@@ -28,8 +28,17 @@ interface RestaurantDetail {
   logo_url: string | null;
   phone: string | null;
   address: string | null;
+  enabled_languages?: string[];
 }
 
+const SUPPORTED_LANGUAGES: { code: string; label: string; flag: string }[] = [
+  { code: "en", label: "İngilizce", flag: "🇬🇧" },
+  { code: "de", label: "Almanca", flag: "🇩🇪" },
+  { code: "ar", label: "Arapça", flag: "🇸🇦" },
+  { code: "ru", label: "Rusça", flag: "🇷🇺" },
+  { code: "fr", label: "Fransızca", flag: "🇫🇷" },
+];
+
 export interface TxtRecord {
   name: string;
   value: string;
@@ -87,6 +96,10 @@ export default function AccountScreen() {
   const [selectedTheme, setSelectedTheme] = useState("elegant");
   const [savingTheme, setSavingTheme] = useState(false);
 
+  // Language / AI Translation state
+  const [enabledLanguages, setEnabledLanguages] = useState<string[]>(["tr"]);
+  const [updatingLanguage, setUpdatingLanguage] = useState<string | null>(null);
+
   // Custom Domain state
   const [domains, setDomains] = useState<DomainRow[]>([]);
   const [newDomainInput, setNewDomainInput] = useState("");
@@ -118,6 +131,7 @@ export default function AccountScreen() {
       setAddress(rest.address ?? "");
       setLogoUrl(rest.logo_url ?? null);
       setSlug(rest.slug);
+      setEnabledLanguages(rest.enabled_languages ?? ["tr"]);
 
       // Fetch theme
       const themeRes = await api.get<{ themeKey: string }>(`/restaurants/${cached.restaurantId}/theme`).catch(() => ({ themeKey: "elegant" }));
@@ -214,6 +228,54 @@ export default function AccountScreen() {
     }
   }
 
+  async function handleAddLanguage(code: string, label: string) {
+    if (!active || updatingLanguage) return;
+    setUpdatingLanguage(code);
+    Haptics.impactAsync(Haptics.ImpactFeedbackStyle.Medium).catch(() => {});
+    try {
+      const res = await api.post<{ enabledLanguages: string[] }>(
+        `/restaurants/${active.restaurantId}/languages`,
+        { code },
+      );
+      setEnabledLanguages(res.enabledLanguages);
+      Haptics.notificationAsync(Haptics.NotificationFeedbackType.Success).catch(() => {});
+      Alert.alert("Menü Çevrildi 🎉", `Menünüz yapay zeka ile ${label} diline çevrildi.`);
+    } catch (err) {
+      Alert.alert("Hata", err instanceof Error ? err.message : "Dil eklenemedi.");
+    } finally {
+      setUpdatingLanguage(null);
+    }
+  }
+
+  async function handleRemoveLanguage(code: string, label: string) {
+    if (!active || updatingLanguage) return;
+    Alert.alert(
+      `${label} Dilini Kaldır`,
+      "Bu dil menüde artık gösterilmeyecek. Çeviriler saklanacağı için dili tekrar eklerseniz yeniden çevrilmesi gerekmez.",
+      [
+        { text: "Vazgeç", style: "cancel" },
+        {
+          text: "Kaldır",
+          style: "destructive",
+          onPress: async () => {
+            setUpdatingLanguage(code);
+            try {
+              const res = await api.delete<{ enabledLanguages: string[] }>(
+                `/restaurants/${active.restaurantId}/languages/${code}`,
+              );
+              setEnabledLanguages(res.enabledLanguages);
+              Haptics.notificationAsync(Haptics.NotificationFeedbackType.Success).catch(() => {});
+            } catch (err) {
+              Alert.alert("Hata", err instanceof Error ? err.message : "Dil kaldırılamadı.");
+            } finally {
+              setUpdatingLanguage(null);
+            }
+          },
+        },
+      ],
+    );
+  }
+
   async function handleAddCustomDomain() {
     if (!active || !newDomainInput.trim()) {
       Alert.alert("Eksik Bilgi", "Lütfen bağlamak istediğiniz alan adını girin (Örn: menu.kebapciahmet.com)");
@@ -605,6 +667,94 @@ export default function AccountScreen() {
           </View>
         </View>
 
+        {/* Language / AI Translation Section */}
+        <View
+          style={{
+            backgroundColor: "#FFFFFF",
+            borderRadius: 20,
+            padding: 20,
+            borderWidth: 1,
+            borderColor: "#E7E5E4",
+            gap: 14,
+          }}
+        >
+          <View style={{ flexDirection: "row", alignItems: "center", gap: 8 }}>
+            <Ionicons name="language-outline" size={20} color="#C8A96B" />
+            <Text style={{ fontSize: 16, fontWeight: "800", color: "#1C1917" }}>
+              Diller (Yapay Zeka Çevirisi)
+            </Text>
+          </View>
+          <Text style={{ fontSize: 12, color: "#78716C", lineHeight: 18 }}>
+            Menünüzü yapay zeka ile otomatik olarak çevirin. Müşterileriniz menüde istedikleri dili seçebilir.
+          </Text>
+
+          <View style={{ flexDirection: "row", flexWrap: "wrap", gap: 8 }}>
+            {/* Turkish — always on, base language */}
+            <View
+              style={{
+                flexDirection: "row",
+                alignItems: "center",
+                gap: 6,
+                backgroundColor: "#1C1917",
+                paddingHorizontal: 12,
+                paddingVertical: 8,
+                borderRadius: 10,
+              }}
+            >
+              <Text style={{ fontSize: 13 }}>🇹🇷</Text>
+              <Text style={{ fontSize: 12, fontWeight: "700", color: "#FFFFFF" }}>Türkçe</Text>
+            </View>
+
+            {SUPPORTED_LANGUAGES.map((lang) => {
+              const isEnabled = enabledLanguages.includes(lang.code);
+              const isUpdating = updatingLanguage === lang.code;
+              return (
+                <Pressable
+                  key={lang.code}
+                  onPress={() =>
+                    isEnabled
+                      ? handleRemoveLanguage(lang.code, lang.label)
+                      : handleAddLanguage(lang.code, lang.label)
+                  }
+                  disabled={isUpdating}
+                  style={{
+                    flexDirection: "row",
+                    alignItems: "center",
+                    gap: 6,
+                    backgroundColor: isEnabled ? "#FDF8F0" : "#FAF8F5",
+                    borderWidth: 1.5,
+                    borderColor: isEnabled ? "#C8A96B" : "#E7E5E4",
+                    paddingHorizontal: 12,
+                    paddingVertical: 8,
+                    borderRadius: 10,
+                    opacity: isUpdating ? 0.6 : 1,
+                  }}
+                >
+                  {isUpdating ? (
+                    <ActivityIndicator size="small" color="#C8A96B" />
+                  ) : (
+                    <Text style={{ fontSize: 13 }}>{lang.flag}</Text>
+                  )}
+                  <Text
+                    style={{
+                      fontSize: 12,
+                      fontWeight: "700",
+                      color: isEnabled ? "#926E27" : "#57534E",
+                    }}
+                  >
+                    {lang.label}
+                  </Text>
+                  {isEnabled ? (
+                    <Ionicons name="close-circle" size={14} color="#C8A96B" />
+                  ) : (
+                    <Ionicons name="add-circle-outline" size={14} color="#A8A29E" />
+                  )}
+                </Pressable>
+              );
+            })}
+          </View>
+        </View>
+
         {/* Custom Domain Section */}
         <View
           style={{