Scaffold dd0c/alert: ingestion, correlation engine, HMAC validation, tests

- Webhook ingestion: HMAC validation for Datadog/PagerDuty/OpsGenie with 5-min timestamp freshness
- Payload normalizers: canonical alert schema with severity mapping per provider
- Correlation engine: time-window grouping, late-alert attachment (2x window), FakeClock for testing
- InMemoryWindowStore for unit tests
- Tests: 12 HMAC validation cases, 5 normalizer cases, 7 correlation engine cases
- PostgreSQL schema with RLS: tenants, incidents, alerts, webhook_secrets, notification_configs
- Free tier enforcement columns (alert_count_month, reset_at)
- Fly.io config, Dockerfile, Gitea Actions CI

products/03-alert-intelligence/package.json

@@ -0,0 +1,36 @@
+{
+  "name": "dd0c-alert",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "tsx watch src/index.ts",
+    "build": "tsc",
+    "start": "node dist/index.js",
+    "test": "vitest run",
+    "lint": "eslint src/ tests/"
+  },
+  "dependencies": {
+    "fastify": "^4.28.0",
+    "@fastify/cors": "^9.0.0",
+    "@fastify/helmet": "^11.1.0",
+    "pg": "^8.12.0",
+    "ioredis": "^5.4.0",
+    "zod": "^3.23.0",
+    "jsonwebtoken": "^9.0.2",
+    "pino": "^9.1.0",
+    "uuid": "^9.0.1",
+    "@aws-sdk/client-sqs": "^3.600.0",
+    "@aws-sdk/client-s3": "^3.600.0"
+  },
+  "devDependencies": {
+    "typescript": "^5.5.0",
+    "tsx": "^4.15.0",
+    "vitest": "^1.6.0",
+    "@types/node": "^20.14.0",
+    "@types/pg": "^8.11.0",
+    "@types/jsonwebtoken": "^9.0.6",
+    "@types/uuid": "^9.0.8",
+    "eslint": "^9.5.0"
+  }
+}