Create dev users only in dev environment, show usernames on login screen dev environment only

[Janell-Huyck]

Summary

This PR updates development seed data and adds development-only login guidance in the UI.

Changes

• Seeds

  • Removed the legacy test user that had no password.
  • Added four new development-only seed users, one per role:
    • root_admin
    • owner
    • manager
    • viewer
  • These users are created only when db:seed is run in development and are not created in other environments.

• UI (Development only)

  • Added a development-only section to the login page (or relevant view) with instructions listing the seeded users and the shared password.

Local development:

Branch deployed to QA/Libappstest

Testing

• ✅ All RSpec tests are still passing.

Notes

• This keeps production/test seed behavior unchanged while providing consistent, role-based accounts for local development and QA.

[scherztc]

Test passed locally.