Add first-time install support to update.sh

Creates systemd service file, enables linger, and starts the service on first
run instead of requiring the service file to already exist.

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

update.sh

@@ -3,14 +3,16 @@ set -e
 
 cd "$(dirname "$0")"
 
+export PATH="$HOME/.bun/bin:/usr/local/go/bin:$HOME/go/bin:$PATH"
+
 SERVICE_FILE="$HOME/.config/systemd/user/webterm.service"
 DEFAULT_USERNAME="izackp"
 DEFAULT_TTL_SECONDS="86400"
 UPDATE_AUTH_PASSWORD=0
 
+INSTALLING=0
 if [ ! -f "$SERVICE_FILE" ]; then
-  echo "Missing service file: $SERVICE_FILE" >&2
-  exit 1
+  INSTALLING=1
 fi
 
 while getopts ":p" opt; do
@@ -26,6 +28,11 @@ while getopts ":p" opt; do
 done
 shift $((OPTIND - 1))
 
+if [ "$INSTALLING" -eq 1 ]; then
+  echo "No service file found — running first-time install."
+  UPDATE_AUTH_PASSWORD=1
+fi
+
 if [ "$UPDATE_AUTH_PASSWORD" -eq 1 ]; then
   echo "Enter password for webterm login."
   read -rsp "Password for $DEFAULT_USERNAME: " WEBTERM_PASSWORD
@@ -36,6 +43,39 @@ if [ "$UPDATE_AUTH_PASSWORD" -eq 1 ]; then
   fi
 fi
 
+if [ "$INSTALLING" -eq 1 ]; then
+  mkdir -p "$(dirname "$SERVICE_FILE")"
+  LOG_DIR="$HOME/.webterm"
+  mkdir -p "$LOG_DIR"
+  BINARY_PATH="$HOME/go/bin/webterm"
+  WORK_DIR="$(pwd)"
+  cat > "$SERVICE_FILE" <<EOF
+[Unit]
+Description=webterm
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+WorkingDirectory=$WORK_DIR
+Environment=HOME=$HOME
+Environment=PATH=/usr/local/go/bin:$HOME/go/bin:$HOME/.bun/bin:/usr/local/bin:/usr/bin:/bin
+ExecStart=$BINARY_PATH
+Restart=on-failure
+RestartSec=5
+StandardOutput=append:$LOG_DIR/server.log
+StandardError=append:$LOG_DIR/server.log
+
+[Install]
+WantedBy=default.target
+EOF
+  echo "Created $SERVICE_FILE"
+  if ! loginctl show-user "$USER" 2>/dev/null | grep -q "Linger=yes"; then
+    echo "Enabling linger for $USER so the service starts at boot without login..."
+    loginctl enable-linger "$USER"
+  fi
+fi
+
 CURRENT_SECRET="$(sed -n 's/^Environment=WEBTERM_AUTH_COOKIE_SECRET=//p' "$SERVICE_FILE" | tail -n 1)"
 if [ -z "$CURRENT_SECRET" ]; then
   CURRENT_SECRET="$(openssl rand -hex 32)"
@@ -110,8 +150,13 @@ mv "$tmp_target" ~/go/bin/webterm
 echo "Reloading user systemd config..."
 systemctl --user daemon-reload
 
-echo "Restarting service..."
-systemctl --user restart webterm.service
+if [ "$INSTALLING" -eq 1 ]; then
+  echo "Enabling and starting service..."
+  systemctl --user enable --now webterm.service
+else
+  echo "Restarting service..."
+  systemctl --user restart webterm.service
+fi
 
 echo "Done. Status:"
 systemctl --user status webterm.service --no-pager