Fix Manyfold Ruby setup home initialization

Create the `manyfold` service user before calling `setup_ruby` so `/home/manyfold` exists when rbenv profile snippets are written. Also harden `setup_ruby` by creating `$HOME` if missing, preventing profile-write failures for installers that pass a home directory before creating the user.

install/manyfold-install.sh

@@ -31,13 +31,16 @@ NODE_VERSION="24" NODE_MODULE="corepack,yarn" setup_nodejs
 
 fetch_and_deploy_gh_release "manyfold" "manyfold3d/manyfold" "tarball" "latest" "/opt/manyfold/app"
 
+# Create the service user (and its home) before setup_ruby, which writes rbenv
+# profile snippets into HOME=/home/manyfold.
+useradd -m -s /usr/bin/bash manyfold
+
 RUBY_INSTALL_VERSION=$(cat /opt/manyfold/app/.ruby-version)
 RUBY_VERSION=${RUBY_INSTALL_VERSION} RUBY_INSTALL_RAILS="true" HOME=/home/manyfold setup_ruby
 
 msg_info "Configuring Manyfold"
 YARN_VERSION=$(grep '"packageManager":' /opt/manyfold/app/package.json | sed -E 's/.*"(yarn@[0-9\.]+)".*/\1/')
 RELEASE=$(get_latest_github_release "manyfold3d/manyfold")
-useradd -m -s /usr/bin/bash manyfold
 cat <<EOF >/opt/manyfold/.env
 export APP_VERSION=${RELEASE}
 export GUID=1002

misc/tools.func

@@ -8637,6 +8637,11 @@ setup_ruby() {
   local BASHRC_FILE="$HOME/.bashrc"
   local TMP_DIR=$(mktemp -d)
 
+  # Ensure HOME exists: callers may pass a not-yet-created home (e.g. a service
+  # user that is created later in the install), so the profile writes below do
+  # not fail on a missing directory.
+  mkdir -p "$HOME"
+
   if ! grep -q 'rbenv init' "$PROFILE_FILE" 2>/dev/null; then
     cat <<'EOF' >>"$PROFILE_FILE"
 export PATH="$HOME/.rbenv/bin:$PATH"