Consolidate @shieldai/db and @shieldsai/shared-db packages (FRE-4603)

- Merged singleton pattern + type exports from shared-db
- Kept FieldEncryptionService from original db package
- Upgraded to Prisma v6.2.0 (newer version)
- Adopted shared-db's complete schema for multi-service platform
- Updated 17 consumer imports across darkwatch, voiceprint, jobs, api
- Standardized on @shieldai/db namespace

Files changed:
- packages/db/package.json (v0.1.0 → v0.2.0)
- packages/db/src/index.ts (consolidated exports)
- packages/db/prisma/schema.prisma (merged schema)
- packages/db/prisma/seed.ts (updated for new schema)
- 17 consumer files updated

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

packages/db/package.json

@@ -1,21 +1,26 @@
 {
   "name": "@shieldai/db",
-  "version": "0.1.0",
-  "main": "./dist/index.js",
-  "types": "./dist/index.js",
+  "version": "0.2.0",
+  "type": "module",
+  "main": "./src/index.ts",
+  "types": "./src/index.ts",
   "scripts": {
     "build": "prisma generate && tsc",
     "db:migrate": "prisma migrate dev",
     "db:seed": "tsx prisma/seed.ts",
     "db:studio": "prisma studio",
+    "db:push": "prisma db push",
+    "db:format": "prisma format",
     "generate": "prisma generate"
   },
   "dependencies": {
     "@prisma/client": "^6.2.0",
-    "prisma": "^6.2.0"
+    "prisma": "^6.2.0",
+    "zod": "^4.3.6"
   },
   "devDependencies": {
-    "tsx": "^4.19.0"
+    "tsx": "^4.19.0",
+    "typescript": "^5.3.3"
   },
   "exports": {
     ".": "./src/index.ts"