feat: add multi-channel subscription blocking UI and admin management

- Channel subscription blocking screen with per-channel status display
- Safe URL handling with protocol validation (no open redirect)
- Race-condition-safe subscription check with useRef guard
- Admin channel management page with create, toggle, delete
- Error handlers on all admin mutations with haptic feedback
- Proper type guard for channel subscription error detection
- Accessibility: aria-labels on icon-only buttons
- Localization: en, ru, zh, fa translations

src/api/adminChannels.ts

@@ -0,0 +1,68 @@
+import apiClient from './client';
+
+// Types
+export interface RequiredChannel {
+  id: number;
+  channel_id: string;
+  channel_link: string | null;
+  title: string | null;
+  is_active: boolean;
+  sort_order: number;
+}
+
+export interface ChannelListResponse {
+  items: RequiredChannel[];
+  total: number;
+}
+
+export interface CreateChannelRequest {
+  channel_id: string;
+  channel_link?: string;
+  title?: string;
+}
+
+export interface UpdateChannelRequest {
+  channel_id?: string;
+  channel_link?: string;
+  title?: string;
+  is_active?: boolean;
+  sort_order?: number;
+}
+
+export const adminChannelsApi = {
+  list: async (): Promise<ChannelListResponse> => {
+    const { data } = await apiClient.get<ChannelListResponse>(
+      '/cabinet/admin/channel-subscriptions',
+    );
+    return data;
+  },
+
+  create: async (req: CreateChannelRequest): Promise<RequiredChannel> => {
+    const { data } = await apiClient.post<RequiredChannel>(
+      '/cabinet/admin/channel-subscriptions',
+      req,
+    );
+    return data;
+  },
+
+  update: async (id: number, req: UpdateChannelRequest): Promise<RequiredChannel> => {
+    const { data } = await apiClient.patch<RequiredChannel>(
+      `/cabinet/admin/channel-subscriptions/${id}`,
+      req,
+    );
+    return data;
+  },
+
+  toggle: async (id: number): Promise<RequiredChannel> => {
+    const { data } = await apiClient.post<RequiredChannel>(
+      `/cabinet/admin/channel-subscriptions/${id}/toggle`,
+    );
+    return data;
+  },
+
+  delete: async (id: number): Promise<void> => {
+    await apiClient.delete(`/cabinet/admin/channel-subscriptions/${id}`);
+  },
+};
+
+export default adminChannelsApi;

src/api/client.ts

@@ -133,6 +133,12 @@ export interface ChannelSubscriptionError {
   code: 'channel_subscription_required';
   message: string;
   channel_link?: string;
+  channels?: Array<{
+    channel_id: string;
+    channel_link?: string;
+    title?: string;
+    is_subscribed: boolean;
+  }>;
 }
 
 export interface BlacklistedError {
@@ -189,6 +195,7 @@ apiClient.interceptors.response.use(
       useBlockingStore.getState().setChannelSubscription({
         message: detail.message,
         channel_link: detail.channel_link,
+        channels: detail.channels,
       });
       return Promise.reject(error);
     }

src/api/index.ts

@@ -12,6 +12,7 @@ export { infoApi } from './info';
 export { adminSettingsApi } from './adminSettings';
 export { adminApi, statsApi } from './admin';
 export { adminAppsApi } from './adminApps';
+export { adminChannelsApi } from './adminChannels';
 export { adminBroadcastsApi } from './adminBroadcasts';
 export { adminEmailTemplatesApi } from './adminEmailTemplates';
 export { adminPaymentMethodsApi } from './adminPaymentMethods';