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/models/am_registration_data.dart

@@ -117,6 +117,16 @@ class AmRegistrationData extends ChangeNotifier {
     required String postalCode,
     required String city,
     String? existingPhotoUrl,
+    bool consentementPhoto = false,
+    DateTime? dateOfBirth,
+    String birthCity = '',
+    String birthCountry = '',
+    String nir = '',
+    String agrementNumber = '',
+    DateTime? agreementDate,
+    int? capacity,
+    int? placesAvailable,
+    String presentationText = '',
   }) {
     this.firstName = firstName;
     this.lastName = lastName;
@@ -130,16 +140,16 @@ class AmRegistrationData extends ChangeNotifier {
     photoPath = existingPhotoUrl;
     photoBytes = null;
     photoFilename = null;
-    photoConsent = false;
-    dateOfBirth = null;
-    birthCity = '';
-    birthCountry = '';
-    nir = '';
-    agrementNumber = '';
-    agreementDate = null;
-    capacity = null;
-    placesAvailable = null;
-    presentationText = '';
+    photoConsent = consentementPhoto;
+    dateOfBirth = dateOfBirth;
+    this.birthCity = birthCity;
+    this.birthCountry = birthCountry;
+    this.nir = nir;
+    this.agrementNumber = agrementNumber;
+    agreementDate = agreementDate;
+    this.capacity = capacity;
+    placesAvailable = placesAvailable;
+    this.presentationText = presentationText;
     cguAccepted = false;
     notifyListeners();
   }
@@ -187,8 +197,8 @@ class AmRegistrationData extends ChangeNotifier {
   bool get isRegistrationComplete =>
       isStep1Complete && isStep2Complete && isStep3Complete;
 
-  /// Reprise (#112) : champs renvoyés par PATCH reprise-resoumettre.
-  bool get isRepriseSubmitReady => isStep1Complete && cguAccepted;
+  /// Reprise (#112) : dossier AM complet renvoyé par PATCH reprise-resoumettre.
+  bool get isRepriseSubmitReady => isRegistrationComplete;
 
   @override
   String toString() {