Actually send the correct image fields to the server

lib/models/exercises/exercise_submission_images.dart

@@ -56,12 +56,12 @@ class ExerciseSubmissionImage {
 
   Map<String, String> toJson() {
     return {
-      'title': title ?? '',
-      'author': author ?? '',
-      'author_url': authorUrl ?? '',
-      'source_url': sourceUrl ?? '',
-      'derivative_source_url': derivativeSourceUrl ?? '',
-      'type': type.id.toString(),
+      'license_title': title ?? '',
+      'license_author': author ?? '',
+      'license_author_url': authorUrl ?? '',
+      'license_object_url': sourceUrl ?? '',
+      'license_derivative_source_url': derivativeSourceUrl ?? '',
+      'style': type.id.toString(),
     };
   }
 }

lib/providers/add_exercise.dart

@@ -192,7 +192,6 @@ class AddExerciseProvider with ChangeNotifier {
       request.fields['exercise'] = exerciseId.toString();
       request.fields['license'] = CC_BY_SA_4_ID.toString();
       request.fields['is_main'] = 'false';
-      request.fields['style'] = ImageType.photo.id.toString();
 
       final details = image.toJson();
       if (details.isNotEmpty) {

lib/widgets/add_exercise/image_details_form.dart

@@ -77,15 +77,14 @@ class _ImageDetailsFormState extends State<ImageDetailsForm> {
       child: Form(
         key: _formKey,
         child: Column(
-          spacing: 8,
           crossAxisAlignment: CrossAxisAlignment.start,
           children: [
             Text(
               AppLocalizations.of(context).imageDetailsTitle,
               style: Theme.of(context).textTheme.titleLarge?.copyWith(fontWeight: FontWeight.bold),
             ),
-            const SizedBox(height: 8),
 
+            const SizedBox(height: 8),
             _buildImagePreview(),
             const SizedBox(height: 8),
 
@@ -93,7 +92,7 @@ class _ImageDetailsFormState extends State<ImageDetailsForm> {
             AddExerciseTextArea(
               title: '${AppLocalizations.of(context).author}*',
               initialValue: widget.submissionImage.author,
-              onSaved: (value) => widget.submissionImage.author = value!,
+              onSaved: (value) => widget.submissionImage.author = value,
               validator: (name) => validateAuthorName(name, context),
             ),
 
@@ -160,35 +159,6 @@ class _ImageDetailsFormState extends State<ImageDetailsForm> {
     );
   }
 
-  Widget _buildTextField({
-    required TextEditingController controller,
-    required String label,
-    String? hint,
-    TextInputType? keyboardType,
-    String? helperText,
-    String? Function(String?)? validator,
-  }) {
-    return Column(
-      crossAxisAlignment: CrossAxisAlignment.start,
-      children: [
-        Text(label, style: const TextStyle(fontSize: 14, fontWeight: FontWeight.w500)),
-        const SizedBox(height: 8),
-        TextFormField(
-          controller: controller,
-          keyboardType: keyboardType,
-          validator: validator,
-          decoration: InputDecoration(
-            hintText: hint,
-            helperText: helperText,
-            helperMaxLines: 3,
-            border: OutlineInputBorder(borderRadius: BorderRadius.circular(4)),
-            contentPadding: const EdgeInsets.symmetric(horizontal: 12, vertical: 12),
-          ),
-        ),
-      ],
-    );
-  }
-
   /// Visual selector for image style/type
   ///
   /// Allows user to categorize the image as PHOTO, 3D render, LINE drawing,
@@ -271,32 +241,7 @@ class _ImageDetailsFormState extends State<ImageDetailsForm> {
             if (!_formKey.currentState!.validate()) {
               return;
             }
-
-            // Add optional fields only if user provided values
-            final title = _titleController.text.trim();
-            if (title.isNotEmpty) {
-              widget.submissionImage.title = title;
-            }
-
-            final author = _authorController.text.trim();
-            if (author.isNotEmpty) {
-              widget.submissionImage.author = author;
-            }
-
-            final sourceUrl = _sourceLinkController.text.trim();
-            if (sourceUrl.isNotEmpty) {
-              widget.submissionImage.sourceUrl = sourceUrl;
-            }
-
-            final authorUrl = _authorLinkController.text.trim();
-            if (authorUrl.isNotEmpty) {
-              widget.submissionImage.authorUrl = authorUrl;
-            }
-
-            final derivativeUrl = _originalSourceController.text.trim();
-            if (derivativeUrl.isNotEmpty) {
-              widget.submissionImage.derivativeSourceUrl = derivativeUrl;
-            }
+            _formKey.currentState?.save();
 
             // Pass image and metadata back to parent
             widget.onAdd(widget.submissionImage);