Document the Proxmox VE LXC Runtime

[philip-ulrich]

Summary

Document the Proxmox VE LXC runtime as part of the existing Wings documentation structure.

The guide covers runtime selection, Proxmox storage and networking, firewall behavior, Tundra private networking, resource reporting, and operational validation. It is linked from the installation navigation and incorporated into the generated configuration reference and existing private-networking documentation.

Changes

• Add a Proxmox LXC installation and operations guide.
• Add the guide to the Wings installation sidebar and overview.
• Document the pve_lxc configuration in the generated Wings configuration reference.
• Extend the existing private-networking guide with LXC-specific behavior.
• Document runtime selection and persistence.
• Cover storage selection, VLAN configuration, allocation handling, firewall modes, and Tundra requirements.

Validation

• pnpm docs:build
• pnpm typecheck
• pnpm biome:validate

All checks passed.

calagopus/wings#34