feat(#132): upload photo à la création d'enfant (admin).

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

frontend/lib/widgets/admin/common/admin_child_detail_modal.dart

@@ -1,4 +1,7 @@
+import 'dart:typed_data';
+
 import 'package:flutter/material.dart';
+import 'package:image_picker/image_picker.dart';
 import 'package:p_tits_pas/models/assistante_maternelle_model.dart';
 import 'package:p_tits_pas/models/enfant_admin_model.dart';
 import 'package:p_tits_pas/services/api/api_config.dart';
@@ -62,6 +65,10 @@ class _AdminChildDetailModalState extends State<AdminChildDetailModal> {
   /// Famille choisie en mode création (#132).
   AdminFamilleFoyer? _selectedFamily;
 
+  /// Photo locale (création) — upload multipart `photo`.
+  Uint8List? _photoBytes;
+  String? _photoFilename;
+
   static const double _modalWidth = 930;
   static const double _mainRowHeight = 380;
   static const double _placementHeight = 96;
@@ -370,11 +377,24 @@ class _AdminChildDetailModalState extends State<AdminChildDetailModal> {
       );
       return;
     }
+    final hasPhoto = _photoBytes != null && _photoBytes!.isNotEmpty;
+    if (hasPhoto && !_consentPhoto) {
+      ScaffoldMessenger.of(context).showSnackBar(
+        const SnackBar(
+          content: Text(
+            'Activez le consentement photo pour enregistrer une photo',
+          ),
+        ),
+      );
+      return;
+    }
 
     setState(() => _saving = true);
     try {
       await UserService.createEnfant(
         parentUserId: family.pivotParentUserId,
+        photoBytes: hasPhoto ? _photoBytes : null,
+        photoFilename: _photoFilename,
         body: {
           'first_name': prenom,
           'last_name': nom,
@@ -383,8 +403,8 @@ class _AdminChildDetailModalState extends State<AdminChildDetailModal> {
           if (_isUnborn)
             if (_dateToIso(_dueCtrl.text) != null)
               'due_date': _dateToIso(_dueCtrl.text)
-          else if (_dateToIso(_birthCtrl.text) != null)
-            'birth_date': _dateToIso(_birthCtrl.text),
+            else if (_dateToIso(_birthCtrl.text) != null)
+              'birth_date': _dateToIso(_birthCtrl.text),
           'consent_photo': _consentPhoto,
           'is_multiple': _isMultiple,
         },
@@ -727,6 +747,43 @@ class _AdminChildDetailModalState extends State<AdminChildDetailModal> {
     );
   }
 
+  Future<void> _pickPhoto() async {
+    if (_busy || !widget.isCreating) return;
+    try {
+      final picked = await ImagePicker().pickImage(
+        source: ImageSource.gallery,
+        imageQuality: 75,
+        maxWidth: 1200,
+        maxHeight: 1200,
+      );
+      if (picked == null) return;
+      final bytes = await picked.readAsBytes();
+      if (bytes.isEmpty) return;
+      final name = picked.name.trim();
+      if (!mounted) return;
+      setState(() {
+        _photoBytes = bytes;
+        _photoFilename = name.isNotEmpty ? name : 'photo.jpg';
+        _consentPhoto = true;
+        _dirty = true;
+      });
+    } catch (_) {
+      if (!mounted) return;
+      ScaffoldMessenger.of(context).showSnackBar(
+        const SnackBar(content: Text('Impossible de charger la photo')),
+      );
+    }
+  }
+
+  void _clearPhoto() {
+    if (_busy || !widget.isCreating) return;
+    setState(() {
+      _photoBytes = null;
+      _photoFilename = null;
+      _dirty = true;
+    });
+  }
+
   Widget _mainRow() {
     return LayoutBuilder(
       builder: (context, c) {
@@ -749,7 +806,20 @@ class _AdminChildDetailModalState extends State<AdminChildDetailModal> {
                 children: [
                   Expanded(
                     child: AdminAmPhotoFrame(
-                      photoUrl: widget.enfant?.photoUrl,
+                      photoUrl: widget.isCreating
+                          ? null
+                          : widget.enfant?.photoUrl,
+                      imageBytes: widget.isCreating ? _photoBytes : null,
+                      onTap: widget.isCreating && !_busy ? _pickPhoto : null,
+                      onClear: widget.isCreating &&
+                              !_busy &&
+                              _photoBytes != null &&
+                              _photoBytes!.isNotEmpty
+                          ? _clearPhoto
+                          : null,
+                      emptyLabel: widget.isCreating
+                          ? 'Cliquer pour ajouter'
+                          : 'Aucune photo',
                     ),
                   ),
                   const SizedBox(height: 8),