feat: add phone frequency controls and modularize codebase

api/src/channels/channels.controller.ts

@@ -4,7 +4,6 @@ import { RequireRecentAuthentication } from '../auth/require-recent-authenticati
 import { CurrentSessionUserId } from '../auth/current-session-user.decorator';
 import { DeleteTargetDto, DeletionGovernanceService } from '../deletion-governance/deletion-governance.service';
 import {
-  ChannelsService,
   ChangeChannelStatusDto,
   CopyChannelDto,
   CreateChannelDto,
@@ -22,7 +21,8 @@ import {
   UpsertConnectionStateDto,
   UpdateChannelDto,
   UpdateChannelGroupDto,
-} from './channels.service';
+} from './channels.contracts';
+import { ChannelsService } from './channels.service';
 
 @ApiTags('channels')
 @Controller('admin')