Added
- Directory documentation surfaced in-app (/docs/directory), help-linked
  from the Directory page, linked from the docs index; extended with slug
  conventions, automatic registration (theta-env seed, ldap-client), and
  the API surface.

Changed
- Direct LDAP binds reframed as first-class (Linux hosts: PAM/SSSD, sudo,
  SSH keys), not 'legacy', across README/DEPLOYMENT/docs/Dockerfile.