fix: photos admin — URL via /api/v1/uploads + static Express

- Nest: servir le volume uploads aussi sous /api/v1/uploads (Traefik /api)
- Flutter: _fullPhotoUrl = base API + chemin /uploads/... (plus d’origine site seul)
- EnfantDossier: tolérer photoUrl camelCase

Made-with: Cursor

frontend/lib/models/dossier_unifie.dart

@@ -203,7 +203,7 @@ class EnfantDossier {
       gender: (json['gender'] ?? json['genre'])?.toString(),
       status: json['status']?.toString(),
       dueDate: json['due_date']?.toString(),
-      photoUrl: json['photo_url']?.toString(),
+      photoUrl: (json['photo_url'] ?? json['photoUrl'])?.toString(),
       consentPhoto: json['consent_photo'] == true,
     );
   }

frontend/lib/widgets/admin/validation_am_wizard.dart

@@ -115,9 +115,8 @@ class _ValidationAmWizardState extends State<ValidationAmWizard> {
     if (url == null || url.trim().isEmpty) return '';
     final u = url.trim();
     if (u.startsWith('http://') || u.startsWith('https://')) return u;
-    final base = ApiConfig.baseUrl;
-    final origin = base.replaceAll(RegExp(r'/api/v1.*'), '');
-    return u.startsWith('/') ? '$origin$u' : '$origin/$u';
+    final base = ApiConfig.baseUrl.replaceAll(RegExp(r'/+$'), '');
+    return u.startsWith('/') ? '$base$u' : '$base/$u';
   }
 
   Widget _buildPhotoSection(AppUser u) {

frontend/lib/widgets/admin/validation_family_wizard.dart

@@ -138,9 +138,9 @@ class _ValidationFamilyWizardState extends State<ValidationFamilyWizard> {
     if (url == null || url.trim().isEmpty) return '';
     final u = url.trim();
     if (u.startsWith('http://') || u.startsWith('https://')) return u;
-    final base = ApiConfig.baseUrl;
-    final origin = base.replaceAll(RegExp(r'/api/v1.*'), '');
-    return u.startsWith('/') ? '$origin$u' : '$origin/$u';
+    // Même origine que l’API : /uploads est servi par Nest sous /api/v1/uploads/ (Traefik n’expose souvent que /api).
+    final base = ApiConfig.baseUrl.replaceAll(RegExp(r'/+$'), '');
+    return u.startsWith('/') ? '$base$u' : '$base/$u';
   }
 
   @override