Dockerize the proxy (all-in-one image) + Docker docs

All-in-one Dockerfile bundling OpenResty + the Node mgmt app + Redis in one
container, mirroring the bare-metal ops/install.sh layout:
- Dockerfile (openresty/openresty:1.31.1.1-2-bookworm-fat base; dumb-init PID 1;
  luarocks install lua-resty-auto-ssl/luasocket/lua-resty-ipmatcher; node 22.x;
  npm ci --omit=dev; OpenResty confs + lua copied into place).
- docker-entrypoint.sh: fallback cert, sed-parameterize RESOLVER/REAL_IP_FROM,
  start bundled redis + node app, exec openresty foreground.
- docker-compose.yml (standalone), .dockerignore, DEPLOYMENT.md.
- nodejs/routes/render.js: /health endpoint for healthchecks.
- nodejs/models/user_ldap.js: tlsOptions forwarded to ldapts Client so the
  proxy can bind ldaps:// with a self-signed cert (app_ldap__tlsOptions__*).
- nodejs/package.json: bump @simpleworkjs/conf to ^1.1.0 (app_* env overrides).
- docs/docker.md + index.md: Docker deployment guide + fronting an SSO Manager.
- ops/proxy.service: add WorkingDirectory=/var/www/proxy/nodejs (bare-metal
  cwd fix so relative conf/ paths resolve).

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

docs/index.md

@@ -19,7 +19,19 @@ A reverse proxy and HTTPS termination service using OpenResty/nginx with a manag
 
 ## Quick Start
 
-### Automated Installation
+### Docker (recommended for self-hosters)
+
+A single all-in-one image bundling OpenResty + the app + Redis:
+
+```bash
+git clone https://github.com/theta42/proxy.git
+cd proxy && docker compose up -d --build
+```
+
+See the [Docker Guide](docker.html) for configuration (OIDC/LDAP via `app_*` env)
+and fronting an SSO Manager.
+
+### Automated bare-metal installation
 
 For modern Debian-based systems (Ubuntu 20.04+, Debian 11+):
 
@@ -27,7 +39,7 @@ For modern Debian-based systems (Ubuntu 20.04+, Debian 11+):
 wget -O - https://raw.githubusercontent.com/theta42/proxy/master/ops/install.sh | sudo bash
 ```
 
-### Requirements
+### Requirements (bare metal)
 
 - Node.js 18+ (tested with 18.x, 20.x, 22.x)
 - OpenResty (nginx with Lua support)
@@ -36,7 +48,8 @@ wget -O - https://raw.githubusercontent.com/theta42/proxy/master/ops/install.sh
 
 ## Documentation
 
-- [Installation Guide](installation.html) - Detailed setup instructions
+- [Docker Guide](docker.html) - All-in-one container deployment + configuration
+- [Installation Guide](installation.html) - Bare-metal setup instructions
 - [API Reference](api.html) - Complete API documentation
 - [Architecture](architecture.html) - System design and components
 - [Contributing](contributing.html) - Development and testing guide