Добавить remote-просмотр исходника карточки

RPC TelegramService.ReadSource + ISessionClient.GetMessageAsync, порт ITelegramGateway.ReadSourceAsync и провайдер TelegramSourceContentProvider в ядре; GET /api/cards/{id}/source догружает исходник у сервиса-владельца, в UI — кнопка «Обновить из источника». Медиа-посты пропускаются.

src/core/Deal.Infrastructure/Integrations/Services/GrpcTelegramClient.cs

@@ -278,6 +278,30 @@ public sealed class GrpcTelegramClient : ITelegramGateway
         }
     }
 
+    /// <inheritdoc />
+    public async Task<TelegramSourceContentDto> ReadSourceAsync(
+        string dialogId,
+        long msgId,
+        CancellationToken ct)
+    {
+        TenantId tenantId = RequireTenant();
+        try
+        {
+            ReadSourceReply reply = await CallAsync(
+                tenantId, TimeSpan.FromSeconds(CommandDeadlineSeconds), ct,
+                (client, options) => client.ReadSourceAsync(
+                    new ReadSourceRequest { DialogId = dialogId ?? string.Empty, MsgId = msgId }, options));
+            return new TelegramSourceContentDto(
+                reply.Found,
+                reply.HasText ? reply.Text : null,
+                reply.HasTime ? reply.Time : null);
+        }
+        catch (Exception exception)
+        {
+            throw TranslateTransportFailure(exception, tenantId, "read_source");
+        }
+    }
+
     /// <inheritdoc />
     public async Task<IReadOnlyList<TelegramDialogEntryDto>> SearchAsync(
         string query,

src/core/Deal.Infrastructure/Integrations/Services/LocalTelegramGateway.cs

@@ -67,6 +67,13 @@ public sealed class LocalTelegramGateway : ITelegramGateway
         CancellationToken ct)
         => Task.FromResult<IReadOnlyList<TelegramRecentMessageDto>>([]);
 
+    /// <inheritdoc />
+    public Task<TelegramSourceContentDto> ReadSourceAsync(
+        string dialogId,
+        long msgId,
+        CancellationToken ct)
+        => Task.FromResult(new TelegramSourceContentDto(false, null, null));
+
     /// <inheritdoc />
     public Task<IReadOnlyList<TelegramDialogEntryDto>> SearchAsync(
         string query,