Fix: FG scan form submission hang and add theme toggle functionality

- Added isAutoSubmitting flag to prevent duplicate validation during auto-submit
- Clear all custom validity states before form submission
- Skip duplicate validation in submit handler when auto-submitting
- Added theme toggle functionality directly to fg_scan page (since script.js is excluded)
- Enhanced logging for debugging form submission flow

This fixes the issue where the form would hang and not send data to the database when defect code was auto-submitted.

py_app/app/templates/fg_scan.html

@@ -133,6 +133,40 @@ function showNotification(message, type = 'info') {
 }
 
 document.addEventListener('DOMContentLoaded', function() {
+    // ========== THEME TOGGLE FUNCTIONALITY ==========
+    const themeToggleButton = document.getElementById('theme-toggle');
+    const body = document.body;
+    
+    // Helper function to update the theme toggle button text
+    function updateThemeToggleButtonText() {
+        if (themeToggleButton) {
+            if (body.classList.contains('dark-mode')) {
+                themeToggleButton.textContent = 'Change to Light Mode';
+            } else {
+                themeToggleButton.textContent = 'Change to Dark Mode';
+            }
+        }
+    }
+    
+    // Check and apply the saved theme from localStorage
+    const savedTheme = localStorage.getItem('theme');
+    if (savedTheme) {
+        body.classList.toggle('dark-mode', savedTheme === 'dark');
+    }
+    
+    // Update the button text based on the current theme
+    updateThemeToggleButtonText();
+    
+    // Toggle the theme on button click
+    if (themeToggleButton) {
+        themeToggleButton.addEventListener('click', () => {
+            const isDarkMode = body.classList.toggle('dark-mode');
+            localStorage.setItem('theme', isDarkMode ? 'dark' : 'light');
+            updateThemeToggleButtonText();
+        });
+    }
+    // ========== END THEME TOGGLE ==========
+    
     // Load toggle state FIRST
     const savedState = localStorage.getItem('scan_to_boxes_enabled');
     if (savedState === 'true') {
@@ -140,6 +174,9 @@ document.addEventListener('DOMContentLoaded', function() {
     }
     console.log('Initial scanToBoxesEnabled:', scanToBoxesEnabled);
     
+    // Flag to prevent duplicate validation during auto-submit
+    let isAutoSubmitting = false;
+    
     const operatorCodeInput = document.getElementById('operator_code');
     const cpCodeInput = document.getElementById('cp_code');
     const oc1CodeInput = document.getElementById('oc1_code');
@@ -679,6 +716,13 @@ document.addEventListener('DOMContentLoaded', function() {
                 return;
             }
             
+            // Clear all custom validity states before submitting
+            operatorCodeInput.setCustomValidity('');
+            cpCodeInput.setCustomValidity('');
+            oc1CodeInput.setCustomValidity('');
+            oc2CodeInput.setCustomValidity('');
+            this.setCustomValidity('');
+            
             // Update time field before submitting
             const timeInput = document.getElementById('time');
             const now = new Date();
@@ -703,15 +747,26 @@ document.addEventListener('DOMContentLoaded', function() {
                 console.log('Auto-submit: Scan-to-boxes enabled, calling submitScanWithBoxAssignment');
                 submitScanWithBoxAssignment();
             } else {
-                console.log('Auto-submit: Normal form submission');
+                console.log('Auto-submit: Normal form submission - setting flag and submitting');
+                isAutoSubmitting = true;
                 // Submit the form normally
+                console.log('Calling form.submit() - form:', form);
                 form.submit();
+                console.log('form.submit() called successfully');
             }
         }
     });
     
     // Validate form on submit
     form.addEventListener('submit', async function(e) {
+        // Skip validation if this is an auto-submit (already validated)
+        if (isAutoSubmitting) {
+            console.log('Auto-submit in progress, skipping duplicate validation');
+            isAutoSubmitting = false;  // Reset flag
+            return true;  // Allow submission to proceed
+        }
+        
+        console.log('Manual form submission, running validation');
         let hasError = false;
         
         if (!operatorCodeInput.value.startsWith('OP')) {