Add internal registry endpoint, self-registration, and workforce sync

- Register internalRoutes at /api/auth/internal (used by management)
- Add registerRoutes for staff self-registration flow
- Add workforce sync job (runs on schedule, fails gracefully if unconfigured)
- Add email.js for registration/invite emails

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

package.json

@@ -12,6 +12,7 @@
     "bcryptjs": "^2.4.3",
     "fastify": "^4.28.1",
     "jose": "^5.9.6",
+    "nodemailer": "^6.10.1",
     "pg": "^8.13.1"
   }
 }