fix(create-proxmox-resource): use absolute path for --pre-format-files

The disko images script does `cd "$TMPDIR"` before parsing its arguments,
so relative paths passed to --pre-format-files resolve against the temp
dir instead of the repo root. Use $(pwd) to capture the absolute repo
path before the disko script changes directory.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

scripts/proxmox/create-proxmox-resource.sh

@@ -487,6 +487,17 @@ nix_extra_opts
 # --- make sure this target has a registered host key --------------------
 echo
 echo "==> Ensuring host key exists and is registered..."
+_host_keyfile="${repo_root}/host-keys/${flake_target}_ssh_host_ed25519_key"
+if [[ ! -f "$_host_keyfile" ]]; then
+  echo "  No host key found for ${flake_target}; generating one via prepare-host-key.sh..."
+  _prepare_host_key="${repo_root}/scripts/secrets/prepare-host-key.sh"
+  if [[ "$dry_run" -eq 1 ]]; then
+    echo "[dry-run] would run: bash ${_prepare_host_key} ${flake_target}"
+  else
+    bash "$_prepare_host_key" "$flake_target"
+  fi
+fi
+unset _host_keyfile _prepare_host_key
 sync_args=("$flake_target")
 [[ "$dry_run" -eq 1 ]] && sync_args+=(--dry-run)
 bash "$sync_keys" "${sync_args[@]}"
@@ -740,8 +751,8 @@ nix build --no-use-registries --no-accept-flake-config "${NIX_OPTS[@]}" \
   ".#nixosConfigurations.${target}.config.system.build.diskoImagesScript" \
   --out-link "result-${target}"
 $sudo_pfx "./result-${target}" \
-  --pre-format-files "host-keys/${target}_ssh_host_ed25519_key" /etc/ssh/ssh_host_ed25519_key \
+  --pre-format-files "$(pwd)/host-keys/${target}_ssh_host_ed25519_key" /etc/ssh/ssh_host_ed25519_key \
-  --pre-format-files "host-keys/${target}_ssh_host_ed25519_key.pub" /etc/ssh/ssh_host_ed25519_key.pub \
+  --pre-format-files "$(pwd)/host-keys/${target}_ssh_host_ed25519_key.pub" /etc/ssh/ssh_host_ed25519_key.pub \
   --build-memory 2048
 built="$(find . -maxdepth 1 -name '*.raw' -newer "result-${target}" | head -1)"
 if [[ -z "$built" ]]; then