Add cross-service alert correlation system FRE-4500

- Unified alert types (AlertSource, AlertCategory, CorrelationStatus, EntityType)
- NormalizedAlert and CorrelationGroup Prisma models
- AlertNormalizer for all 4 services (DarkWatch, SpamShield, VoicePrint, CallAnalysis)
- CorrelationEngine with temporal + entity-based correlation detection
- CorrelationService orchestrator with dashboard API
- Correlation API routes (/api/v1/correlation/*)
- Service emitters wired to DarkWatch, SpamShield, VoicePrint
- pnpm workspace config for monorepo

package.json

@@ -22,5 +22,6 @@
   },
   "engines": {
     "node": ">=20.0.0"
-  }
+  },
+  "packageManager": "pnpm@9.0.0"
 }