feat: Add VM/LXC cloning functionality

[michelroegl-brunner]

Overview

This PR adds comprehensive VM/LXC cloning functionality to the application.

Features

• Clone VMs and LXC containers with configurable count
• Sequential ID retrieval (get next ID → clone → get next ID → clone, etc.)
• Storage selection for clones (rootdir content only)
• Hostname generation for cloned containers
• Integration with VM/LXC detection from main branch
• Real-time clone execution tracking via WebSocket

Changes

• New CloneCountInputModal component for specifying clone count
• Extended InstalledScriptsTab with clone handlers and state management
• Added clone menu item to ScriptInstallationCard
• Extended StorageSelectionModal to support clone storage selection
• Added clone terminal support to Terminal component
• Implemented startSSHCloneExecution in server.js with sequential ID retrieval
• Added clone-related API endpoints:
  • getClusterNextId - Get single next available ID
  • getContainerType - Determine if container is VM or LXC
  • getCloneStorages - Get storages suitable for cloning (rootdir only)
  • generateCloneHostnames - Generate unique hostnames for clones
  • executeClone - Execute clone operation
  • addClonedContainerToDatabase - Add cloned container to database

Technical Details

• Uses new VM/LXC detection logic from main branch
• Sequential ID retrieval ensures each clone gets a unique ID
• Storage filtering limited to rootdir content for cloning
• Proper error handling and user feedback
• TypeScript types and JSDoc annotations updated

Testing

• Build passes without errors
• All TypeScript and linting checks pass
• Clone functionality tested with both VMs and LXC containers