feat: supervisor module — team performance + active calls endpoints

- SupervisorService: aggregates Ozonetel agent summary across all agents,
  tracks active calls from real-time events
- GET /api/supervisor/team-performance — per-agent time breakdown + thresholds
- GET /api/supervisor/active-calls — current active call map
- POST /api/supervisor/call-event — Ozonetel event webhook
- POST /api/supervisor/agent-event — Ozonetel agent event webhook

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/supervisor/supervisor.module.ts

@@ -0,0 +1,12 @@
+import { Module } from '@nestjs/common';
+import { PlatformModule } from '../platform/platform.module';
+import { OzonetelAgentModule } from '../ozonetel/ozonetel-agent.module';
+import { SupervisorController } from './supervisor.controller';
+import { SupervisorService } from './supervisor.service';
+
+@Module({
+    imports: [PlatformModule, OzonetelAgentModule],
+    controllers: [SupervisorController],
+    providers: [SupervisorService],
+})
+export class SupervisorModule {}