feat: recording analysis module with Deepgram + AI insights + Redis cache

- RecordingsModule: POST /api/recordings/analyze
- Deepgram pre-recorded API: diarize, summarize, topics, sentiment, utterances
- AI insights via OpenAI generateObject: call outcome, coaching, compliance, satisfaction
- Redis cache: 7-day TTL per callId, check before hitting Deepgram/OpenAI
- Generic getCache/setCache added to SessionService for cross-module use

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

src/app.module.ts

@@ -14,6 +14,7 @@ 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';
+import { RecordingsModule } from './recordings/recordings.module';
 
 @Module({
     imports: [
@@ -34,6 +35,7 @@ import { MaintModule } from './maint/maint.module';
         SearchModule,
         SupervisorModule,
         MaintModule,
+        RecordingsModule,
     ],
 })
 export class AppModule {}