Fix version display and backup permission issues

Fixed two issues preventing the Electron update from working properly:

1. Log messages appearing in version output
   - get_latest_electron_version() was outputting log messages to stdout
   - These messages were being captured along with the version number
   - Result: "Target version: [INFO] Fetching...39.2.3" in output
   - Fix: Redirect log_info and log_error to stderr with >&2
   - Now only the version number is captured in the variable

2. Backup function permission errors
   - stat command needed sudo to read owner of restricted directories
   - File checks [ -f ] couldn't access files in drwxr-x--- directories
   - mkdir failed with "cannot create directory '/home/kiosk': Permission denied"
   - Fix: Use sudo for all file operations in create_backup():
     * sudo stat -c '%U' to get directory owner
     * sudo test -f/d for file/directory checks
     * sudo -u owner for mkdir, cp, and file writes

Changes in both update_electron.sh and install_kiosk_0.9.2-6.sh:
- get_latest_electron_version functions: Added >&2 to log statements
- create_backup functions: Added sudo to stat and all file checks
- Ensures backup works with restricted /home/kiosk permissions

The update process should now complete successfully without permission errors
or garbled version output.

install_kiosk_0.9.2-6.sh

@@ -8343,7 +8343,7 @@ manual_electron_update() {
 
     # Function to get latest electron version
     get_latest_electron_version_local() {
-        log_info "Fetching latest stable Electron version from npm..."
+        log_info "Fetching latest stable Electron version from npm..." >&2
 
         local version=""
 
@@ -8472,24 +8472,25 @@ manual_electron_update() {
     # Create backup
     echo ""
     log_info "Creating backup..."
+    local kiosk_owner=$(sudo stat -c '%U' "$KIOSK_DIR")
     local timestamp=$(date +%Y%m%d_%H%M%S)
     local backup_dir="${KIOSK_DIR}/backups/electron_backup_${timestamp}"
 
-    mkdir -p "$backup_dir"
+    sudo -u "$kiosk_owner" mkdir -p "$backup_dir"
 
     # Backup package.json and package-lock.json
-    if [ -f "$KIOSK_DIR/package.json" ]; then
-        cp "$KIOSK_DIR/package.json" "$backup_dir/"
+    if sudo test -f "$KIOSK_DIR/package.json" 2>/dev/null; then
+        sudo -u "$kiosk_owner" cp "$KIOSK_DIR/package.json" "$backup_dir/"
         log_success "Backed up package.json"
     fi
 
-    if [ -f "$KIOSK_DIR/package-lock.json" ]; then
-        cp "$KIOSK_DIR/package-lock.json" "$backup_dir/"
+    if sudo test -f "$KIOSK_DIR/package-lock.json" 2>/dev/null; then
+        sudo -u "$kiosk_owner" cp "$KIOSK_DIR/package-lock.json" "$backup_dir/"
         log_success "Backed up package-lock.json"
     fi
 
     # Save current Electron version
-    echo "$CURRENT_VERSION" > "$backup_dir/electron_version.txt"
+    echo "$CURRENT_VERSION" | sudo -u "$kiosk_owner" tee "$backup_dir/electron_version.txt" > /dev/null
     log_success "Backup created at: $backup_dir"
     echo ""
 

update_electron.sh

@@ -145,7 +145,7 @@ check_electron_running() {
 ################################################################################
 
 get_latest_electron_version() {
-    log_info "Fetching latest stable Electron version from npm..."
+    log_info "Fetching latest stable Electron version from npm..." >&2
 
     # Try multiple methods to get the latest version
     local version=""
@@ -164,7 +164,7 @@ get_latest_electron_version() {
     fi
 
     if [ -z "$version" ]; then
-        log_error "Failed to fetch latest Electron version"
+        log_error "Failed to fetch latest Electron version" >&2
         echo "unknown"
         return 1
     fi
@@ -178,7 +178,7 @@ get_latest_electron_version() {
 
 create_backup() {
     local kiosk_dir="$1"
-    local kiosk_owner=$(stat -c '%U' "$kiosk_dir")
+    local kiosk_owner=$(sudo stat -c '%U' "$kiosk_dir")
     local timestamp=$(date +%Y%m%d_%H%M%S)
     BACKUP_DIR="${kiosk_dir}/backups/electron_backup_${timestamp}"
 
@@ -188,18 +188,18 @@ create_backup() {
     sudo -u "$kiosk_owner" mkdir -p "$BACKUP_DIR"
 
     # Backup package.json and package-lock.json
-    if [ -f "$kiosk_dir/package.json" ]; then
+    if sudo test -f "$kiosk_dir/package.json" 2>/dev/null; then
         sudo -u "$kiosk_owner" cp "$kiosk_dir/package.json" "$BACKUP_DIR/"
         log_success "Backed up package.json"
     fi
 
-    if [ -f "$kiosk_dir/package-lock.json" ]; then
+    if sudo test -f "$kiosk_dir/package-lock.json" 2>/dev/null; then
         sudo -u "$kiosk_owner" cp "$kiosk_dir/package-lock.json" "$BACKUP_DIR/"
         log_success "Backed up package-lock.json"
     fi
 
     # Create a list of installed packages
-    if [ -d "$kiosk_dir/node_modules" ]; then
+    if sudo test -d "$kiosk_dir/node_modules" 2>/dev/null; then
         sudo -u "$kiosk_owner" bash -c "ls -1 '$kiosk_dir/node_modules' > '$BACKUP_DIR/installed_packages.txt'"
         log_success "Created list of installed packages"
     fi