Dockerize SSO Manager (all-in-one image) + GitHub Pages docs

All-in-one Dockerfile.openldap bundling the app + OpenLDAP + Redis in one
container, plus an idempotent bare-metal install.sh, and a Jekyll docs site
for GitHub Pages:
- Dockerfile.openldap (node:20-alpine; openldap + pw-sha2/ppolicy/memberof/
  refint; dumb-init PID 1; npm ci --omit=dev; tos.md copied to /).
- docker-entrypoint.sh: generate slapd.conf (mdb + overlays + TLS + indexes +
  access), self-signed LDAPS cert, seed directory tree + required groups,
  bundled redis, export app_* config, exec node.
- docker-compose.yml, .dockerignore, DEPLOYMENT.md, secrets.js.example.
- install.sh: idempotent Debian/Ubuntu bare-metal installer (Node 20.x,
  OpenLDAP, Redis, systemd unit) with flags + --dry-run/--skip-ldap/--skip-app.
- ops/ldif/: memberof/refint/tls/index/nodes/logging LDIFs.
- nodejs/conf/base.js: generic defaults (dc=example,dc=com / localhost /
  SSO Manager) so per-deployment values move to secrets.js or app_* env.
- nodejs/package.json: bump @simpleworkjs/conf to ^1.1.0 (app_* env overrides).
- nodejs/routes/index.js: /health endpoint for healthchecks.
- docs/: _config.yml + index/deployment/configuration/oauth/ldap pages
  (jekyll-theme-cayman) for GitHub Pages from /docs.

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

docs/_config.yml

@@ -0,0 +1,9 @@
+title: SSO Manager
+description: A self-hosted OpenID Connect provider with an OpenLDAP directory and a web management UI
+theme: jekyll-theme-cayman
+show_downloads: true
+github:
+  repository_url: https://github.com/theta42/sso-manager-node
+  zip_url: https://github.com/theta42/sso-manager-node/archive/refs/heads/master.zip
+  tar_url: https://github.com/theta42/sso-manager-node/archive/refs/heads/master.tar.gz
+  repository_name: theta42/sso-manager-node