feat(cost): add zombie hunter, Slack interactions, composite scoring

- Zombie resource hunter: detects idle EC2/RDS/EBS/EIP/NAT resources
- Slack interactive handler: acknowledge, snooze, create-ticket actions
- Composite anomaly scorer: Z-Score + rate-of-change + pattern + novelty
- Cold-start fast path for new resources (<7 days data)
- 005_zombies.sql migration

products/05-aws-cost-anomaly/package-lock.json

@@ -31,7 +31,7 @@
         "eslint": "^9.5.0",
         "fast-check": "^3.19.0",
         "tsx": "^4.15.0",
-        "typescript": "^5.5.0",
+        "typescript": "^5.9.3",
         "vitest": "^1.6.0"
       }
     },
@@ -3813,9 +3813,9 @@
       }
     },
     "node_modules/flatted": {
-      "version": "3.3.3",
-      "resolved": "https://registry.npmjs.org/flatted/-/flatted-3.3.3.tgz",
-      "integrity": "sha512-GX+ysw4PBCz0PzosHDepZGANEuFCMLrnRTiEy9McGjmkCQYwRq4A/X786G/fjM/+OjsWSU1ZrY5qyARZmO/uwg==",
+      "version": "3.3.4",
+      "resolved": "https://registry.npmjs.org/flatted/-/flatted-3.3.4.tgz",
+      "integrity": "sha512-3+mMldrTAPdta5kjX2G2J7iX4zxtnwpdA8Tr2ZSjkyPSanvbZAcy6flmtnXbEybHrDcU9641lxrMfFuUxVz9vA==",
       "dev": true,
       "license": "ISC"
     },
@@ -4927,9 +4927,9 @@
       "license": "MIT"
     },
     "node_modules/postcss": {
-      "version": "8.5.6",
-      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.5.6.tgz",
-      "integrity": "sha512-3Ybi1tAuwAP9s0r1UQ2J4n5Y0G05bJkpUIO0/bI9MhwmD70S5aTWbXGBwxHrelT+XM1k6dM0pk+SwNkpTRN7Pg==",
+      "version": "8.5.8",
+      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.5.8.tgz",
+      "integrity": "sha512-OW/rX8O/jXnm82Ey1k44pObPtdblfiuWnrd8X7GJ7emImCOstunGbXUpp7HdBrFQX6rJzn3sPT397Wp5aCwCHg==",
       "dev": true,
       "funding": [
         {