fix: pi-setup.sh substitutes actual username when installing systemd units

Service files had User=olafn and /home/olafn/ hardcoded. pi-setup.sh now
uses ACTUAL_USER=${SUDO_USER:-$USER} and sed-substitutes at install time
so units work on any Pi regardless of the OS user.

src/pi-setup.sh

@@ -18,7 +18,11 @@ log_warn() { echo -e "${YELLOW}⚠️  $1${NC}"; }
 log_err()  { echo -e "${RED}❌ $1${NC}"; }
 
 # Configuration
-PROJECT_DIR="$HOME/infoscreen-dev"
+# Resolve the actual unprivileged user even when the script is invoked via sudo.
+ACTUAL_USER="${SUDO_USER:-$USER}"
+ACTUAL_HOME="$(eval echo "~$ACTUAL_USER")"
+
+PROJECT_DIR="$ACTUAL_HOME/infoscreen-dev"
 REPO_URL="https://github.com/RobbStarkAustria/infoscreen-client-dev-2025.git"  # Public HTTPS clone
 VENV_DIR="$PROJECT_DIR/venv"
 REQ_FILE="$PROJECT_DIR/src/requirements.txt"
@@ -148,8 +152,11 @@ SYSTEMD_DIR="/etc/systemd/system"
 
 for unit in infoscreen-simclient.service infoscreen-display.service "infoscreen-notify-failure@.service"; do
   if [ -f "$SERVICES_SRC/$unit" ]; then
-    sudo cp "$SERVICES_SRC/$unit" "$SYSTEMD_DIR/$unit"
-    log_ok "Installed $SYSTEMD_DIR/$unit"
+    # Substitute the dev-machine username/home with the actual target user.
+    sed -e "s|olafn|$ACTUAL_USER|g" \
+        -e "s|/home/$ACTUAL_USER|$ACTUAL_HOME|g" \
+        "$SERVICES_SRC/$unit" | sudo tee "$SYSTEMD_DIR/$unit" > /dev/null
+    log_ok "Installed $SYSTEMD_DIR/$unit (user=$ACTUAL_USER)"
   else
     log_warn "Service unit not found: $SERVICES_SRC/$unit"
   fi