Fix: Add safe localStorage wrapper and QZ Tray toggle feature

- Created storage-utils.js with safeStorage wrapper to prevent tracking prevention errors
- Updated script.js to use safeStorage for theme persistence
- Added conditional QZ Tray connection based on 'Enable Scan to Boxes' toggle
- Fixed 404 error by removing non-existent /api/backup/path endpoint call
- Enhanced fg_scan.html to disable QZ Tray and socket connections when toggle is off
- Prevents console errors when browser tracking prevention blocks localStorage access

py_app/app/static/script.js

@@ -1,3 +1,29 @@
+// Safe localStorage wrapper to handle tracking prevention
+const safeStorage = {
+    getItem: function(key) {
+        try {
+            return localStorage.getItem(key);
+        } catch (e) {
+            console.warn('localStorage access blocked:', e);
+            return null;
+        }
+    },
+    setItem: function(key, value) {
+        try {
+            localStorage.setItem(key, value);
+        } catch (e) {
+            console.warn('localStorage access blocked:', e);
+        }
+    },
+    removeItem: function(key) {
+        try {
+            localStorage.removeItem(key);
+        } catch (e) {
+            console.warn('localStorage access blocked:', e);
+        }
+    }
+};
+
 document.addEventListener('DOMContentLoaded', () => {
     const reportButtons = document.querySelectorAll('.report-btn');
     const reportTitle = document.getElementById('report-title');
@@ -17,7 +43,7 @@ document.addEventListener('DOMContentLoaded', () => {
     }
 
     // Check and apply the saved theme from localStorage
-    const savedTheme = localStorage.getItem('theme');
+    const savedTheme = safeStorage.getItem('theme');
     if (savedTheme) {
         body.classList.toggle('dark-mode', savedTheme === 'dark');
     }
@@ -28,7 +54,7 @@ document.addEventListener('DOMContentLoaded', () => {
     // Toggle the theme on button click
     themeToggleButton.addEventListener('click', () => {
         const isDarkMode = body.classList.toggle('dark-mode');
-        localStorage.setItem('theme', isDarkMode ? 'dark' : 'light');
+        safeStorage.setItem('theme', isDarkMode ? 'dark' : 'light');
         updateThemeToggleButtonText(); // Update the button text after toggling
     });