feat: SSE agent state, maint module, timestamp fix, missed call lead lookup

- SSE agent state stream: supervisor maintains state map from Ozonetel webhooks, streams via /api/supervisor/agent-state/stream
- Force-logout via SSE: distinct force-logout event type avoids conflict with normal login cycle
- Maint module (/api/maint): OTP-guarded endpoints for force-ready, unlock-agent, backfill-missed-calls, fix-timestamps
- Fix Ozonetel IST→UTC timestamp conversion: istToUtc() in webhook controller and missed-queue service
- Missed call lead lookup: ingestion queries leads by phone, stores leadId + leadName on Call entity
- Timestamp backfill endpoint: throttled at 700ms/mutation, idempotent (skips already-fixed records)
- Structured logging: full JSON payloads for agent/call webhooks, [DISPOSE] trace with agentId
- Fix dead code: agent-state endpoint auto-assign was after return statement
- Export SupervisorService for cross-module injection

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

src/app.module.ts

@@ -13,6 +13,7 @@ import { WorklistModule } from './worklist/worklist.module';
 import { CallAssistModule } from './call-assist/call-assist.module';
 import { SearchModule } from './search/search.module';
 import { SupervisorModule } from './supervisor/supervisor.module';
+import { MaintModule } from './maint/maint.module';
 
 @Module({
     imports: [
@@ -32,6 +33,7 @@ import { SupervisorModule } from './supervisor/supervisor.module';
         CallAssistModule,
         SearchModule,
         SupervisorModule,
+        MaintModule,
     ],
 })
 export class AppModule {}