FRE-4517, FRE-4499: Complete SpamShield implementation and billing updates

- SpamFeedback table migration with timestamp index
- Real-time interception engine completion
- Billing service enhancements
- Classifier and rule engine updates

Co-Authored-By: Paperclip <noreply@paperclip.ing>

services/spamshield/package.json

@@ -11,6 +11,7 @@
   },
   "dependencies": {
     "@shieldai/db": "0.1.0",
+    "@shieldai/types": "0.1.0",
     "@prisma/client": "^6.2.0",
     "libphonenumber-js": "^1.10.50",
     "ws": "^8.16.0"