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

packages/integration-tests/src/fixtures/test-db.ts

@@ -0,0 +1,28 @@
+import type { PrismaClient } from '@shieldai/db';
+
+let prisma: PrismaClient | null = null;
+
+export async function initializeTestDB(): Promise<PrismaClient> {
+  if (!prisma) {
+    // eslint-disable-next-line @typescript-eslint/no-var-requires
+    process.env.DATABASE_URL = process.env.DATABASE_URL || 'postgresql://test:test@localhost:5432/test';
+    const db = await import('@shieldai/db');
+    const PC = (db as unknown as { PrismaClient: new () => PrismaClient }).PrismaClient;
+    prisma = new PC();
+  }
+  return prisma;
+}
+
+export async function cleanupTestDB(): Promise<void> {
+  if (prisma) {
+    await prisma.$disconnect();
+    prisma = null;
+  }
+}
+
+export function getTestDB(): PrismaClient {
+  if (!prisma) {
+    throw new Error('Test database not initialized. Call initializeTestDB() first.');
+  }
+  return prisma;
+}