fix(deploy): embed prisma migrate deploy in API startup

- Move prisma to runtime dependencies so it's available in prod image
- API runs migrate deploy before starting (handles fresh installs + updates)
- Remove separate migrate service from prod compose

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/api/package.json

@@ -21,6 +21,7 @@
     "@nestjs/platform-express": "^11.0.0",
     "@nestjs/schedule": "^6.1.3",
     "@prisma/client": "^6.0.0",
+    "prisma": "^6.0.0",
     "@tessera/shared": "workspace:*",
     "argon2": "^0.44.0",
     "class-transformer": "^0.5.1",
@@ -50,7 +51,6 @@
     "@types/nodemailer": "^8.0.1",
     "@types/passport-jwt": "^4.0.1",
     "@types/passport-local": "^1.0.38",
-    "prisma": "^6.0.0",
     "typescript": "^5.5.0"
   }
 }