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>

ops/ldif/refint2.ldif

@@ -0,0 +1,7 @@
+dn: olcOverlay={1}refint,olcDatabase={1}mdb,cn=config
+objectClass: olcConfig
+objectClass: olcOverlayConfig
+objectClass: olcRefintConfig
+objectClass: top
+olcOverlay: {1}refint
+olcRefintAttribute: memberof member manager owner