Justfile: add commands to switch yubikey

Justfile

@@ -241,3 +241,17 @@ run-with-channels +cmds:
 	#!/usr/bin/env bash
 	source $(just -v _get_nix_path {{invocation_directory()}}/nix/variables/versions.nix)
 	{{cmds}}
+
+# Switch between yubikeys which have a copy of the same key
+switch-yubikey:
+	#!/usr/bin/env bash
+	# See https://github.com/drduh/YubiKey-Guide/issues/19
+	set -xe
+	KEY_ID=$(gpg --card-status | rg sec | rg -o '[0-9A-Z]{16}')
+	gpg --delete-secret-and-public-keys $KEY_ID
+	gpg2 --edit-card <<-EOF
+	fetch
+	quit
+	EOF
+	gpg-connect-agent "scd serialno" "learn --force" /bye
+	gpg --card-status