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/recordings/recordings.module.ts

@@ -0,0 +1,11 @@
+import { Module } from '@nestjs/common';
+import { AuthModule } from '../auth/auth.module';
+import { RecordingsController } from './recordings.controller';
+import { RecordingsService } from './recordings.service';
+
+@Module({
+    imports: [AuthModule],
+    controllers: [RecordingsController],
+    providers: [RecordingsService],
+})
+export class RecordingsModule {}