feat: Node.js 24 and 26 images; refuse builds below the Oct 2026 security floor

- One install-node.sh <major> replaces install-node{18,20,22}.sh. It fails the
  build if NodeSource hands back a version below the newest security release
  for the line (22.23.4 / 24.22.1 / 26.12.1: CVE-2026-111497 Brotli OOB write
  and 9 others), so a lagging mirror can't ship a vulnerable image silently.
  18 and 20 are EOL: they still build, with a warning.
- CI matrix adds 24 and 26; fail-fast off so one line can't cancel the rest.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -1,6 +1,6 @@
 # Cloud Node Container
 
-This is a base container for running Node.js applications, supporting multiple Node.js versions (18, 20, 22). The default is Node.js 20. The container is based on AlmaLinux 10 and uses Nginx as a reverse proxy with SSL. It is designed for both development and production use.
+This is a base container for running Node.js applications, supporting multiple Node.js versions (18, 20, 22, 24, 26). The default is Node.js 20. The container is based on AlmaLinux 10 and uses Nginx as a reverse proxy with SSL. It is designed for both development and production use.
 
 **You must have Docker or compatible containerization software running.**
 
@@ -8,7 +8,7 @@ This is a base container for running Node.js applications, supporting multiple N
 
 ## What's Included?
 
-- **Multiple Node.js Versions:** 18, 20, 22 (set with `NODEVER` or `-a` flag)
+- **Multiple Node.js Versions:** 18, 20, 22, 24, 26 (set with `NODEVER` or `-a` flag)
 - **PM2 Process Manager:** For production-grade Node.js application management
 - **Nginx Reverse Proxy:** SSL-enabled reverse proxy with automatic HTTP to HTTPS redirect
 - **Development Features:** Memcached for sessions, automatic backups, log rotation
@@ -227,7 +227,7 @@ When you place your app in `user/app/`, the container automatically:
 
 ## Features
 
-- **Multiple Node.js Versions:** 18, 20, 22 (set with `NODEVER` environment variable)
+- **Multiple Node.js Versions:** 18, 20, 22, 24, 26 (set with `NODEVER` environment variable)
 - **Process Management:** PM2 for production-grade Node.js application management
 - **Reverse Proxy:** Nginx handles SSL termination and proxies requests to Node.js
 - **WebSockets:** socket.io and `ws` supported out of the box (see [WebSocket Support](#websocket-support-socketio-ws))
@@ -250,7 +250,7 @@ When you place your app in `user/app/`, the container automatically:
 **Optional:**
 - `environment` – Set to `DEV` to start Redis and enable development features
 - `serveralias` – Comma-separated list of alternative hostnames
-- `NODEVER` – Node.js version (18, 20, 22)
+- `NODEVER` – Node.js version (18, 20, 22, 24, 26)
 
 ---