feat: add ButtonsTab for per-section button style customization

Visual editor in admin settings for configuring Telegram button colors
and custom emoji IDs per menu section. Includes API client, draft state
management, save/reset, and translations for ru/en/fa/zh locales.

src/locales/en.json

@@ -1217,6 +1217,7 @@
       "noSearchResults": "Nothing found",
       "example": "Example",
       "analytics": "Analytics",
+      "buttons": "Buttons",
       "notConfigured": "Not configured",
       "counterActive": "Active",
       "counterInactive": "Inactive",
@@ -1286,6 +1287,35 @@
       "quickPresets": "Quick presets",
       "saturation": "Saturation"
     },
+    "buttons": {
+      "color": "Button color",
+      "emojiId": "Custom Emoji ID",
+      "emojiPlaceholder": "Custom emoji ID (optional)",
+      "resetAll": "Reset all styles",
+      "sections": {
+        "home": "Home",
+        "subscription": "Subscription",
+        "balance": "Balance",
+        "referral": "Referrals",
+        "support": "Support",
+        "info": "Info",
+        "admin": "Admin Panel"
+      },
+      "descriptions": {
+        "home": "Personal cabinet button",
+        "subscription": "Subscription management",
+        "balance": "Top-up and balance",
+        "referral": "Referral program",
+        "support": "Support tickets",
+        "info": "Information section",
+        "admin": "Web admin panel"
+      },
+      "styles": {
+        "primary": "Blue",
+        "success": "Green",
+        "danger": "Red"
+      }
+    },
     "apps": {
       "title": "App Management",
       "addApp": "Add App",

src/locales/fa.json

@@ -935,6 +935,7 @@
       "noSearchResults": "چیزی یافت نشد",
       "example": "مثال",
       "analytics": "تحلیل‌ها",
+      "buttons": "دکمه‌ها",
       "notConfigured": "پیکربندی نشده",
       "counterActive": "فعال",
       "counterInactive": "غیرفعال",
@@ -995,6 +996,35 @@
       "resetAllColors": "بازنشانی همه رنگ‌ها",
       "statusColors": "رنگ‌های وضعیت"
     },
+    "buttons": {
+      "color": "رنگ دکمه",
+      "emojiId": "شناسه ایموجی سفارشی",
+      "emojiPlaceholder": "شناسه ایموجی سفارشی (اختیاری)",
+      "resetAll": "بازنشانی همه سبک‌ها",
+      "sections": {
+        "home": "صفحه اصلی",
+        "subscription": "اشتراک",
+        "balance": "موجودی",
+        "referral": "معرفی",
+        "support": "پشتیبانی",
+        "info": "اطلاعات",
+        "admin": "پنل مدیریت"
+      },
+      "descriptions": {
+        "home": "دکمه کابینت شخصی",
+        "subscription": "مدیریت اشتراک",
+        "balance": "شارژ و موجودی",
+        "referral": "برنامه معرفی",
+        "support": "تیکت‌های پشتیبانی",
+        "info": "بخش اطلاعات",
+        "admin": "پنل مدیریت وب"
+      },
+      "styles": {
+        "primary": "آبی",
+        "success": "سبز",
+        "danger": "قرمز"
+      }
+    },
     "apps": {
       "title": "مدیریت برنامه‌ها",
       "addApp": "افزودن برنامه",

src/locales/ru.json

@@ -1260,6 +1260,7 @@
       "branding": "Брендинг",
       "theme": "Тема",
       "analytics": "Аналитика",
+      "buttons": "Кнопки",
       "payments": "Платежи",
       "subscriptions": "Подписки",
       "interface": "Интерфейс",
@@ -1801,6 +1802,35 @@
         "MODERATION": "Модерация"
       }
     },
+    "buttons": {
+      "color": "Цвет кнопки",
+      "emojiId": "Custom Emoji ID",
+      "emojiPlaceholder": "ID кастомного эмодзи (необязательно)",
+      "resetAll": "Сбросить все стили",
+      "sections": {
+        "home": "Главная",
+        "subscription": "Подписка",
+        "balance": "Баланс",
+        "referral": "Рефералы",
+        "support": "Поддержка",
+        "info": "Информация",
+        "admin": "Админка"
+      },
+      "descriptions": {
+        "home": "Кнопка личного кабинета",
+        "subscription": "Управление подпиской",
+        "balance": "Пополнение и баланс",
+        "referral": "Реферальная программа",
+        "support": "Обращения в поддержку",
+        "info": "Информационный раздел",
+        "admin": "Веб-админка"
+      },
+      "styles": {
+        "primary": "Синий",
+        "success": "Зелёный",
+        "danger": "Красный"
+      }
+    },
     "apps": {
       "title": "Управление приложениями",
       "addApp": "Добавить приложение",

src/locales/zh.json

@@ -973,6 +973,7 @@
       "noSearchResults": "未找到结果",
       "example": "示例",
       "analytics": "分析",
+      "buttons": "按钮",
       "notConfigured": "未配置",
       "counterActive": "已启用",
       "counterInactive": "未启用",
@@ -1033,6 +1034,35 @@
       "resetAllColors": "重置所有颜色",
       "statusColors": "状态颜色"
     },
+    "buttons": {
+      "color": "按钮颜色",
+      "emojiId": "自定义表情 ID",
+      "emojiPlaceholder": "自定义表情 ID（可选）",
+      "resetAll": "重置所有样式",
+      "sections": {
+        "home": "主页",
+        "subscription": "订阅",
+        "balance": "余额",
+        "referral": "推荐",
+        "support": "支持",
+        "info": "信息",
+        "admin": "管理面板"
+      },
+      "descriptions": {
+        "home": "个人中心按钮",
+        "subscription": "订阅管理",
+        "balance": "充值和余额",
+        "referral": "推荐计划",
+        "support": "支持工单",
+        "info": "信息板块",
+        "admin": "网页管理面板"
+      },
+      "styles": {
+        "primary": "蓝色",
+        "success": "绿色",
+        "danger": "红色"
+      }
+    },
     "apps": {
       "title": "应用管理",
       "addApp": "添加应用",