[#101] [Frontend] Inscription parent — API, soumission et validation

Squash merge de develop vers master.

Livrables principaux (ticket #101 et mise au point associée) :
- Branchement du formulaire d'inscription parent sur POST /api/v1/auth/register/parent
- Payload DTO (parents, enfants, photos base64, CGU) et services Auth
- Parcours gestionnaire : cartes dossiers, wizard validation famille, images authentifiées
- Scripts d'inscription test (Martin, Durand/Rousseau, Lecomte) ; .gitignore .cursor/

Inclut également les ajustements develop fusionnés dans ce lot (inscription AM, champs relais, etc.).

Closes #101

Made-with: Cursor

frontend/lib/widgets/custom_app_text_field.dart

@@ -32,6 +32,9 @@ class CustomAppTextField extends StatefulWidget {
   final TextInputAction? textInputAction;
   final ValueChanged<String>? onFieldSubmitted;
   final List<TextInputFormatter>? inputFormatters;
+  final bool autocorrect;
+  final bool enableSuggestions;
+  final GlobalKey<FormFieldState<String>>? formFieldKey;
 
   const CustomAppTextField({
     super.key,
@@ -57,6 +60,9 @@ class CustomAppTextField extends StatefulWidget {
     this.textInputAction,
     this.onFieldSubmitted,
     this.inputFormatters,
+    this.autocorrect = true,
+    this.enableSuggestions = true,
+    this.formFieldKey,
   });
 
   @override
@@ -78,9 +84,13 @@ class _CustomAppTextFieldState extends State<CustomAppTextField> {
 
   @override
   Widget build(BuildContext context) {
-    const double fontHeightMultiplier = 1.2;
-    const double internalVerticalPadding = 16.0;
     final double dynamicFieldHeight = widget.fieldHeight;
+    // Indication « non éditable » : libellé + hint en gris.
+    final Color labelColor =
+        widget.enabled ? Colors.black87 : Colors.grey;
+    final Color hintColor = widget.enabled
+        ? Colors.black54.withValues(alpha: 0.7)
+        : Colors.grey;
 
     return Column(
       crossAxisAlignment: CrossAxisAlignment.start,
@@ -91,16 +101,18 @@ class _CustomAppTextFieldState extends State<CustomAppTextField> {
             widget.labelText,
             style: GoogleFonts.merienda(
               fontSize: widget.labelFontSize,
-              color: Colors.black87,
+              color: labelColor,
               fontWeight: FontWeight.w500,
             ),
           ),
           const SizedBox(height: 6),
         ],
+        // Pas de hauteur fixe sur le TextFormField : le message d’erreur du
+        // validateur s’affiche en dessous ; un SizedBox fixe le masquait.
         SizedBox(
           width: widget.fieldWidth,
-          height: dynamicFieldHeight,
           child: Stack(
+            clipBehavior: Clip.none,
             alignment: Alignment.centerLeft,
             children: [
               Positioned.fill(
@@ -112,48 +124,63 @@ class _CustomAppTextFieldState extends State<CustomAppTextField> {
               Padding(
                 padding:
                     const EdgeInsets.symmetric(horizontal: 18.0, vertical: 8.0),
-                child: TextFormField(
-                  controller: widget.controller,
-                  focusNode: widget.focusNode,
-                  obscureText: widget.obscureText,
-                  keyboardType: widget.keyboardType,
-                  inputFormatters: widget.inputFormatters,
-                  autofillHints: widget.autofillHints,
-                  textInputAction: widget.textInputAction,
-                  onFieldSubmitted: widget.onFieldSubmitted,
-                  enabled: widget.enabled,
-                  readOnly: widget.readOnly,
-                  onTap: widget.onTap,
-                  style: GoogleFonts.merienda(
-                      fontSize: widget.inputFontSize,
-                      color: widget.enabled ? Colors.black87 : Colors.grey),
-                  validator: widget.validator ??
-                      (value) {
-                        if (!widget.enabled || widget.readOnly) return null;
-                        if (widget.isRequired &&
-                            (value == null || value.isEmpty)) {
-                          return 'Ce champ est obligatoire';
-                        }
-                        return null;
-                      },
-                  decoration: InputDecoration(
-                    hintText: widget.hintText,
-                    hintStyle: GoogleFonts.merienda(
+                child: ConstrainedBox(
+                  constraints: BoxConstraints(
+                    minHeight:
+                        (dynamicFieldHeight - 16.0).clamp(24.0, double.infinity),
+                  ),
+                  child: TextFormField(
+                    key: widget.formFieldKey,
+                    controller: widget.controller,
+                    focusNode: widget.focusNode,
+                    obscureText: widget.obscureText,
+                    keyboardType: widget.keyboardType,
+                    autocorrect: widget.autocorrect,
+                    enableSuggestions: widget.enableSuggestions,
+                    inputFormatters: widget.inputFormatters,
+                    autofillHints: widget.autofillHints,
+                    textInputAction: widget.textInputAction,
+                    onFieldSubmitted: widget.onFieldSubmitted,
+                    enabled: widget.enabled,
+                    readOnly: widget.readOnly,
+                    onTap: widget.onTap,
+                    style: GoogleFonts.merienda(
                         fontSize: widget.inputFontSize,
-                        color: Colors.black54.withOpacity(0.7)),
-                    border: InputBorder.none,
-                    contentPadding: EdgeInsets.zero,
-                    suffixIcon: widget.suffixIcon != null
-                        ? Padding(
-                            padding: const EdgeInsets.only(right: 0.0),
-                            child: Icon(widget.suffixIcon,
-                                color: Colors.black54,
-                                size: widget.inputFontSize * 1.1),
-                          )
-                        : null,
-                    isDense: true,
+                        color: Colors.black87),
+                    validator: widget.validator ??
+                        (value) {
+                          if (!widget.enabled || widget.readOnly) return null;
+                          if (widget.isRequired &&
+                              (value == null || value.isEmpty)) {
+                            return 'Ce champ est obligatoire';
+                          }
+                          return null;
+                        },
+                    decoration: InputDecoration(
+                      hintText: widget.hintText,
+                      hintStyle: GoogleFonts.merienda(
+                          fontSize: widget.inputFontSize,
+                          color: hintColor),
+                      border: InputBorder.none,
+                      contentPadding: EdgeInsets.zero,
+                      isDense: true,
+                      errorStyle: GoogleFonts.merienda(
+                        fontSize: widget.inputFontSize * 0.75,
+                        color: Colors.red.shade800,
+                        height: 1.2,
+                      ),
+                      errorMaxLines: 3,
+                      suffixIcon: widget.suffixIcon != null
+                          ? Padding(
+                              padding: const EdgeInsets.only(right: 0.0),
+                              child: Icon(widget.suffixIcon,
+                                  color: Colors.black54,
+                                  size: widget.inputFontSize * 1.1),
+                            )
+                          : null,
+                    ),
+                    textAlignVertical: TextAlignVertical.center,
                   ),
-                  textAlignVertical: TextAlignVertical.center,
                 ),
               ),
             ],