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/maint/maint.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 { AuthModule } from '../auth/auth.module';
+import { SupervisorModule } from '../supervisor/supervisor.module';
+import { MaintController } from './maint.controller';
+
+@Module({
+    imports: [PlatformModule, OzonetelAgentModule, AuthModule, SupervisorModule],
+    controllers: [MaintController],
+})
+export class MaintModule {}