feat(front): inscription parent — genre obligatoire H/F/Autre (#101)

- ChildData.genre + copyWith ; liste déroulante sur la carte enfant
- Validation et payload API alignés sur GenreType
- Étape 3 : mises à jour via copyWith (préservation du genre)

Made-with: Cursor

frontend/lib/widgets/child_card_widget.dart

@@ -19,6 +19,8 @@ class ChildCardWidget extends StatefulWidget {
   final VoidCallback onDateSelect;
   final ValueChanged<String> onFirstNameChanged;
   final ValueChanged<String> onLastNameChanged;
+  /// `H`, `F` ou `Autre` (GenreType API).
+  final ValueChanged<String> onGenreChanged;
   final ValueChanged<bool> onTogglePhotoConsent;
   final ValueChanged<bool> onToggleMultipleBirth;
   final ValueChanged<bool> onToggleIsUnborn;
@@ -35,6 +37,7 @@ class ChildCardWidget extends StatefulWidget {
     required this.onDateSelect,
     required this.onFirstNameChanged,
     required this.onLastNameChanged,
+    required this.onGenreChanged,
     required this.onTogglePhotoConsent,
     required this.onToggleMultipleBirth,
     required this.onToggleIsUnborn,
@@ -190,6 +193,8 @@ class _ChildCardWidgetState extends State<ChildCardWidget> {
                 hint: 'Nom de l\'enfant',
               ),
               SizedBox(height: 8.0 * scaleFactor),
+              _buildGenreField(context, config, scaleFactor),
+              SizedBox(height: 8.0 * scaleFactor),
               _buildField(
                 config: config,
                 scaleFactor: scaleFactor,
@@ -352,6 +357,8 @@ class _ChildCardWidgetState extends State<ChildCardWidget> {
                           const SizedBox(height: 12),
                           _buildReadonlyField('Nom :', _lastNameController.text),
                           const SizedBox(height: 12),
+                          _buildReadonlyField('Genre :', _genreDisplayLabel(widget.childData.genre)),
+                          const SizedBox(height: 12),
                           _buildReadonlyField(
                             widget.childData.isUnbornChild ? 'Date prévisionnelle :' : 'Date de naissance :',
                             _dobController.text
@@ -467,6 +474,8 @@ class _ChildCardWidgetState extends State<ChildCardWidget> {
                     const SizedBox(height: 8),
                     _buildReadonlyField('Nom :', _lastNameController.text),
                     const SizedBox(height: 8),
+                    _buildReadonlyField('Genre :', _genreDisplayLabel(widget.childData.genre)),
+                    const SizedBox(height: 8),
                     _buildReadonlyField(
                       widget.childData.isUnbornChild ? 'Date prévisionnelle :' : 'Date de naissance :',
                       _dobController.text
@@ -556,6 +565,72 @@ class _ChildCardWidgetState extends State<ChildCardWidget> {
     );
   }
 
+  static String _genreDisplayLabel(String g) {
+    switch (g) {
+      case 'H':
+        return 'Garçon';
+      case 'F':
+        return 'Fille';
+      case 'Autre':
+        return 'Autre / ne souhaite pas préciser';
+      default:
+        return '';
+    }
+  }
+
+  Widget _buildGenreField(BuildContext context, DisplayConfig config, double scaleFactor) {
+    if (config.isReadonly) {
+      return FormFieldWrapper(
+        config: config,
+        label: 'Genre',
+        value: _genreDisplayLabel(widget.childData.genre),
+      );
+    }
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        Text(
+          'Genre *',
+          style: GoogleFonts.merienda(
+            fontSize: config.isMobile ? 12.0 : 18.0 * scaleFactor,
+            fontWeight: FontWeight.w600,
+          ),
+        ),
+        SizedBox(height: 4.0 * scaleFactor),
+        Container(
+          width: double.infinity,
+          padding: EdgeInsets.symmetric(horizontal: 14.0 * scaleFactor, vertical: 4.0),
+          decoration: BoxDecoration(
+            image: const DecorationImage(
+              image: AssetImage('assets/images/bg_beige.png'),
+              fit: BoxFit.fill,
+            ),
+            borderRadius: BorderRadius.circular(8 * scaleFactor),
+          ),
+          child: DropdownButtonHideUnderline(
+            child: DropdownButton<String>(
+              isExpanded: true,
+              value: widget.childData.genre.isEmpty ? null : widget.childData.genre,
+              hint: Text('Choisir', style: GoogleFonts.merienda(fontSize: config.isMobile ? 13.0 : 16.0)),
+              style: GoogleFonts.merienda(fontSize: config.isMobile ? 13.0 : 16.0, color: Colors.black87),
+              items: [
+                DropdownMenuItem(value: 'H', child: Text('Garçon', style: GoogleFonts.merienda())),
+                DropdownMenuItem(value: 'F', child: Text('Fille', style: GoogleFonts.merienda())),
+                DropdownMenuItem(
+                  value: 'Autre',
+                  child: Text('Autre / ne souhaite pas préciser', style: GoogleFonts.merienda()),
+                ),
+              ],
+              onChanged: (v) {
+                if (v != null) widget.onGenreChanged(v);
+              },
+            ),
+          ),
+        ),
+      ],
+    );
+  }
+
   Widget _buildField({
     required DisplayConfig config,
     required double scaleFactor,