Remove nixos scaffold placeholder to allow git subtree add

nixos/README.md

@@ -1,49 +0,0 @@
-# nixos/
-
-NixOS flake — manages all NixOS hosts via a platform × build-type matrix.
-This directory will be populated via `git subtree` from the existing `nixos` repo.
-
-## Migration (Phase 4 of implementation plan)
-
-```bash
-# From the repo root — do this once:
-git subtree add --prefix=nixos /home/wayne/repos/nixos main --squash
-
-# To pull future updates:
-git subtree pull --prefix=nixos /home/wayne/repos/nixos main --squash
-```
-
-## After migration
-
-The flake works from the subdirectory. Update references on NixOS hosts:
-
-```bash
-# The Switch-nix / Test-nix aliases reference the flake URL.
-# Update from (example):
-#   git+ssh://gitea.lan.ddnsgeek.com/wayne/nixos
-# To:
-#   git+ssh://gitea.lan.ddnsgeek.com/wayne/infrastructure?dir=nixos
-```
-
-## Hosts managed
-
-| Target | Role | Platform |
-|--------|------|---------|
-| `proxmox-docker` | Docker app stack host | Proxmox LXC |
-| `proxmox-nix-cache` | Nix binary cache + remote builder | Proxmox LXC |
-| `proxmox-pxe-boot` | Network boot server | Proxmox LXC |
-| `proxmox-tailscale-router` | Tailscale subnet router | Proxmox LXC |
-| `proxmox-ha-server-1/2` | HA file server cluster | Proxmox VMs |
-| `baremetal-gui` | Daily-driver workstation | Bare metal |
-
-## Key commands
-
-```bash
-# Build without switching (validate)
-nix build ./nixos#proxmox-docker
-
-# Deploy to a host
-nixos-rebuild switch --flake ./nixos#proxmox-docker --target-host docker.sweet.home
-
-# Or use the Switch-nix alias on the NixOS host itself
-```