feat(docker): add guided install and saved one-command updates

src/test/docker-install-harness.sh

@@ -0,0 +1,10 @@
+# No Docker, permissions or external services are modified by wizard tests.
+docker() { return 0; }
+uname() { echo Linux; }
+flock() { :; }
+export -f docker uname flock
+install() { :; }
+chown() { :; }
+stat() { echo 33:33; }
+sudo() { "$@"; }
+export -f install chown stat sudo