Install gen-admin-password alongside vetting

proxmox-install.sh + install.sh left operators with no way to
generate the bcrypt hash on the LXC — 'vetting gen-admin-password'
was suggested in the post-install message but the binary has no
subcommands. Cross-build gen-admin-password-linux-amd64 during the
one-liner flow and drop it into /usr/local/bin.

deploy/proxmox-install.sh

@@ -65,9 +65,9 @@ fi
 echo "==> installing templ ${TEMPL_VERSION}"
 GOBIN=/usr/local/bin go install "github.com/a-h/templ/cmd/templ@${TEMPL_VERSION}"
 
-echo "==> building orchestrator (make orchestrator-linux)"
+echo "==> building orchestrator + gen-admin-password"
 cd "${SRC_DIR}"
-make orchestrator-linux
+make orchestrator-linux gen-admin-password-linux
 
 echo "==> running deploy/install.sh"
 bash deploy/install.sh --binary "bin/vetting-linux-amd64"