Initial commit: Docker install skill for Ubuntu LXC containers

- Install Docker 28.0.4 (LXC-compatible)
- Auto-configure Proxmox host permissions
- Support Ubuntu 20.04/22.04/24.04
- Include troubleshooting guide

PLUGIN.md

@@ -0,0 +1,30 @@
+---
+name: docker-install
+description: Install Docker and docker-compose on Ubuntu LXC containers (Proxmox VE)
+version: 1.0.0
+author: Your Name
+---
+
+# Docker Install Plugin
+
+Quickly install Docker and docker-compose on empty Ubuntu LXC containers with automatic LXC compatibility handling.
+
+## Installation
+
+\`\`\`bash
+claude plugin install https://github.com/YOUR_USERNAME/docker-install-plugin
+\`\`\`
+
+## Usage
+
+Invoke the skill:
+- `/docker-install` - Full guided installation
+- Or describe: "Install Docker on this CT"
+
+## What It Does
+
+- Detects LXC container type (privileged/unprivileged)
+- Configures Proxmox host device permissions
+- Installs Docker 28.0.4 (LXC-compatible, avoids runc 1.3.4 issues)
+- Verifies installation with hello-world test
+- Optionally locks versions to prevent upgrades