feat(#112): aligner reprise front sur dossier complet GET/PATCH

Préremplit parents, enfants, motivation et fiche AM depuis reprise-dossier
et envoie le body PATCH complet (co-parent, enfants par id, champs pro AM).

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/lib/services/reprise_session.dart

@@ -2,6 +2,7 @@ import 'package:p_tits_pas/models/am_registration_data.dart';
 import 'package:p_tits_pas/models/reprise_dossier.dart';
 import 'package:p_tits_pas/models/user_registration_data.dart';
 import 'package:p_tits_pas/services/api/api_config.dart';
+import 'package:p_tits_pas/utils/reprise_mapper.dart';
 
 /// Contexte reprise après refus (token e-mail ou identify). Ticket #112.
 class RepriseSession {
@@ -10,6 +11,7 @@ class RepriseSession {
   static String? _token;
   static String? _role;
   static String? _photoUrl;
+  static String? _photoUrlForApi;
 
   static bool get isActive =>
       _token != null && _token!.trim().isNotEmpty;
@@ -20,16 +22,22 @@ class RepriseSession {
 
   static bool get isAm => _role == 'assistante_maternelle';
 
+  /// URL absolue pour l'affichage.
   static String? get photoUrl => _photoUrl;
 
+  /// Chemin relatif API (`/uploads/…`) pour PATCH sans re-upload.
+  static String? get photoUrlForApi => _photoUrlForApi;
+
   static void start({
     required String token,
     required RepriseDossier dossier,
   }) {
     _token = token.trim();
     _role = dossier.role;
-    _photoUrl = dossier.photoUrl?.trim().isNotEmpty == true
-        ? ApiConfig.absoluteMediaUrl(dossier.photoUrl)
+    final raw = dossier.photoUrl?.trim();
+    _photoUrlForApi = raw != null && raw.isNotEmpty ? raw : null;
+    _photoUrl = _photoUrlForApi != null
+        ? ApiConfig.absoluteMediaUrl(_photoUrlForApi)
         : null;
   }
 
@@ -37,22 +45,15 @@ class RepriseSession {
     _token = null;
     _role = null;
     _photoUrl = null;
+    _photoUrlForApi = null;
   }
 
   static void applyToParent(UserRegistrationData data, RepriseDossier dossier) {
-    data.resetForReprise(
-      firstName: dossier.prenom ?? '',
-      lastName: dossier.nom ?? '',
-      phone: dossier.telephone ?? '',
-      email: dossier.email,
-      address: dossier.adresse ?? '',
-      postalCode: dossier.codePostal ?? '',
-      city: dossier.ville ?? '',
-    );
+    RepriseMapper.applyParentDossier(data, dossier);
   }
 
   static void applyToAm(AmRegistrationData data, RepriseDossier dossier) {
-    final photo = _photoUrl;
+    final displayPhoto = _photoUrl;
     data.resetForReprise(
       firstName: dossier.prenom ?? '',
       lastName: dossier.nom ?? '',
@@ -61,7 +62,17 @@ class RepriseSession {
       streetAddress: dossier.adresse ?? '',
       postalCode: dossier.codePostal ?? '',
       city: dossier.ville ?? '',
-      existingPhotoUrl: photo,
+      existingPhotoUrl: displayPhoto,
+      consentementPhoto: dossier.consentementPhoto ?? false,
+      dateOfBirth: RepriseMapper.parseIsoDate(dossier.dateNaissance),
+      birthCity: dossier.lieuNaissanceVille ?? '',
+      birthCountry: dossier.lieuNaissancePays ?? '',
+      nir: dossier.nir ?? '',
+      agrementNumber: dossier.numeroAgrement ?? '',
+      agreementDate: RepriseMapper.parseIsoDate(dossier.dateAgrement),
+      capacity: dossier.nbMaxEnfants,
+      placesAvailable: dossier.placeDisponible,
+      presentationText: dossier.biographie ?? '',
     );
   }
 }