feat(hosts): make config multi-host and add vps host

Parametrize networking, users, and containers modules under
myNetworking/myUsers/myContainers so both hosts share the same logic
instead of duplicating it, and split desktop/server module imports
into modules/profiles/. Adds hosts/vps (not installed yet, hardware
config and bootloader device are placeholders) to run Traefik,
Headscale, Headplane, and Gitea via a combined Docker Compose stack.

Wires up agenix for secrets and migrates miku-homelab's WireGuard
private key off a plain filesystem path into an encrypted
secrets/miku-homelab-wg.age. The vps side of that tunnel still needs
its own key generated and encrypted after install.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

secrets/miku-homelab-wg.age

@@ -0,0 +1,9 @@
+age-encryption.org/v1
+-> ssh-ed25519 IW6ZLQ fGdkbwV5VE8c5ueKCr/q3Agl9cKnqzmpPUGQsOTMqVU
+ZvXNujDfCWxuprM/2k7FR7aeNcpwU+cAd9H+ZByYOkE
+-> ssh-ed25519 h0IYxQ 3PzwNp8Sn8eeYBNMBKOJ+hoH9uxVlgV0RtqsPdZNtnM
+WDLCfjfmKsj3u0GL+luYLwwXit98RLbgwMBNzp+x24U
+-> ssh-ed25519 4D7N4w 3ndiKKCZSJoZNpn1HElFnyPOx8DeFJPm9iAMQdtm4SM
+KqX/oScwxOhOqHM1Z+uoXWMRZrCpl5ax6BuHiy6puwc
+--- CEVnIJUTA60ffvNCDrodud14KIfucXHub+tl7tXX/N4
+ÅШb³ú_zj(Ãö…s>îãF¼x£UßãFعÝÓÛñS·ˆ`†ŸOdÙ…N‰lÛFã%š LfÇ—FfÞ‡#ê6ò‘ðÎ