Fix color synchronization between admin panel and frontend

Fixed field name mismatch causing colors to display incorrectly:
- Frontend uses 'bojaHex' while backend expects 'boja_hex'
- Added bidirectional field transformation in API service layer
- Ensures hex color codes are properly saved and retrieved
- Also prevents editing of Bambu Lab predefined color hex codes

🤖 Generated with [Claude Code](https://claude.ai/code)

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

app/upadaj/colors/page.tsx

@@ -3,6 +3,7 @@
 import { useState, useEffect } from 'react';
 import { useRouter } from 'next/navigation';
 import { colorService } from '@/src/services/api';
+import { bambuLabColors, getColorHex } from '@/src/data/bambuLabColorsComplete';
 import '@/src/styles/select.css';
 
 interface Color {
@@ -307,6 +308,10 @@ function ColorForm({
     name: color.name || '',
     hex: color.hex || '#000000',
   });
+  
+  // Check if this is a Bambu Lab predefined color
+  const isBambuLabColor = !!(formData.name && bambuLabColors.hasOwnProperty(formData.name));
+  const bambuHex = formData.name ? getColorHex(formData.name) : null;
 
   const handleChange = (e: React.ChangeEvent<HTMLInputElement>) => {
     const { name, value } = e.target;
@@ -318,9 +323,12 @@ function ColorForm({
 
   const handleSubmit = (e: React.FormEvent) => {
     e.preventDefault();
+    // Use Bambu Lab hex if it's a predefined color
+    const hexToSave = isBambuLabColor && bambuHex ? bambuHex : formData.hex;
     onSave({
       ...color,
-      ...formData
+      name: formData.name,
+      hex: hexToSave
     });
   };
 
@@ -351,22 +359,29 @@ function ColorForm({
             <input
               type="color"
               name="hex"
-              value={formData.hex}
+              value={isBambuLabColor && bambuHex ? bambuHex : formData.hex}
               onChange={handleChange}
-              className="w-12 h-12 p-1 border-2 border-gray-300 dark:border-gray-600 rounded-md cursor-pointer"
-              style={{ backgroundColor: formData.hex }}
+              disabled={isBambuLabColor}
+              className={`w-12 h-12 p-1 border-2 border-gray-300 dark:border-gray-600 rounded-md ${isBambuLabColor ? 'cursor-not-allowed opacity-60' : 'cursor-pointer'}`}
+              style={{ backgroundColor: isBambuLabColor && bambuHex ? bambuHex : formData.hex }}
             />
             <input
               type="text"
               name="hex"
-              value={formData.hex}
+              value={isBambuLabColor && bambuHex ? bambuHex : formData.hex}
               onChange={handleChange}
               required
+              readOnly={isBambuLabColor}
               pattern="^#[0-9A-Fa-f]{6}$"
               placeholder="#000000"
-              className="flex-1 px-3 py-2 border border-gray-300 dark:border-gray-600 rounded-md bg-white dark:bg-gray-700 text-gray-900 dark:text-gray-100 focus:outline-none focus:ring-2 focus:ring-blue-500"
+              className={`flex-1 px-3 py-2 border border-gray-300 dark:border-gray-600 rounded-md bg-white dark:bg-gray-700 text-gray-900 dark:text-gray-100 focus:outline-none focus:ring-2 focus:ring-blue-500 ${isBambuLabColor ? 'bg-gray-100 dark:bg-gray-900 cursor-not-allowed' : ''}`}
             />
           </div>
+          {isBambuLabColor && (
+            <p className="text-xs text-gray-500 dark:text-gray-400 mt-1">
+              Bambu Lab predefinisana boja - hex kod se ne može menjati
+            </p>
+          )}
         </div>
 
         <div className="md:col-span-2 flex justify-end gap-4 mt-4">