feat(frontend): NIR 15 car., formatage, validation, widget dédié (#102)

- nir_utils: normalizeNir, formatNir, validateNir (format + clé), Corse 2A/2B
- NirInputFormatter: formatage auto à la saisie (espaces + tiret)
- NirTextField: widget réutilisable pour champ NIR
- professional_info_form_screen: NIR 15 car., affichage formaté à l'init
- custom_app_text_field: paramètre inputFormatters

Refs: #102
Made-with: Cursor

frontend/lib/widgets/professional_info_form_screen.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 import 'package:google_fonts/google_fonts.dart';
 import 'package:go_router/go_router.dart';
 import 'package:intl/intl.dart';
@@ -6,7 +7,9 @@ import 'dart:math' as math;
 import 'dart:io';
 import '../models/card_assets.dart';
 import '../config/display_config.dart';
+import '../utils/nir_utils.dart';
 import 'custom_app_text_field.dart';
+import 'nir_text_field.dart';
 import 'form_field_wrapper.dart';
 import 'app_custom_checkbox.dart';
 import 'hover_relief_widget.dart';
@@ -97,7 +100,8 @@ class _ProfessionalInfoFormScreenState extends State<ProfessionalInfoFormScreen>
           : '';
       _birthCityController.text = data.birthCity;
       _birthCountryController.text = data.birthCountry;
-      _nirController.text = data.nir;
+      final nirRaw = nirToRaw(data.nir);
+      _nirController.text = nirRaw.length == 15 ? formatNir(nirRaw) : data.nir;
       _agrementController.text = data.agrementNumber;
       _capacityController.text = data.capacity?.toString() ?? '';
       _photoPathFramework = data.photoPath;
@@ -161,7 +165,7 @@ class _ProfessionalInfoFormScreenState extends State<ProfessionalInfoFormScreen>
         dateOfBirth: _selectedDate,
         birthCity: _birthCityController.text,
         birthCountry: _birthCountryController.text,
-        nir: _nirController.text,
+        nir: normalizeNir(_nirController.text),
         agrementNumber: _agrementController.text,
         capacity: int.tryParse(_capacityController.text),
       );
@@ -499,7 +503,7 @@ class _ProfessionalInfoFormScreenState extends State<ProfessionalInfoFormScreen>
                             children: [
                               Expanded(flex: 2, child: _buildReadonlyField('Date de naissance', _dateOfBirthController.text)),
                               const SizedBox(width: 16),
-                              Expanded(flex: 3, child: _buildReadonlyField('NIR', _nirController.text)),
+                              Expanded(flex: 3, child: _buildReadonlyField('NIR', _formatNirForDisplay(_nirController.text))),
                             ],
                           ),
                           const SizedBox(height: 12),
@@ -525,6 +529,12 @@ class _ProfessionalInfoFormScreenState extends State<ProfessionalInfoFormScreen>
     );
   }
 
+  /// NIR formaté pour affichage (1 12 34 56 789 012-34 ou 2A pour la Corse).
+  String _formatNirForDisplay(String value) {
+    final raw = nirToRaw(value);
+    return raw.length == 15 ? formatNir(raw) : value;
+  }
+
   /// Helper pour champ Readonly style "Beige"
   Widget _buildReadonlyField(String label, String value) {
     return Column(
@@ -609,18 +619,12 @@ class _ProfessionalInfoFormScreenState extends State<ProfessionalInfoFormScreen>
           ],
         ),
         SizedBox(height: verticalSpacing),
-        _buildField(
-          config: config,
-          label: 'N° Sécurité Sociale (NIR)',
+        NirTextField(
           controller: _nirController,
-          hint: 'Votre NIR à 13 chiffres',
-          keyboardType: TextInputType.number,
-          validator: (v) {
-            if (v == null || v.isEmpty) return 'NIR requis';
-            if (v.length != 13) return 'Le NIR doit contenir 13 chiffres';
-            if (!RegExp(r'^[1-3]').hasMatch(v[0])) return 'Le NIR doit commencer par 1, 2 ou 3';
-            return null;
-          },
+          fieldWidth: double.infinity,
+          fieldHeight: config.isMobile ? 45.0 : 53.0,
+          labelFontSize: config.isMobile ? 15.0 : 22.0,
+          inputFontSize: config.isMobile ? 14.0 : 20.0,
         ),
         SizedBox(height: verticalSpacing),
         Row(
@@ -695,18 +699,12 @@ class _ProfessionalInfoFormScreenState extends State<ProfessionalInfoFormScreen>
         ),
         const SizedBox(height: 12),
         
-        _buildField(
-          config: config,
-          label: 'N° Sécurité Sociale (NIR)',
+        NirTextField(
           controller: _nirController,
-          hint: 'Votre NIR à 13 chiffres',
-          keyboardType: TextInputType.number,
-          validator: (v) {
-            if (v == null || v.isEmpty) return 'NIR requis';
-            if (v.length != 13) return 'Le NIR doit contenir 13 chiffres';
-            if (!RegExp(r'^[1-3]').hasMatch(v[0])) return 'Le NIR doit commencer par 1, 2 ou 3';
-            return null;
-          },
+          fieldWidth: double.infinity,
+          fieldHeight: 45.0,
+          labelFontSize: 15.0,
+          inputFontSize: 14.0,
         ),
         const SizedBox(height: 12),
         
@@ -796,6 +794,7 @@ class _ProfessionalInfoFormScreenState extends State<ProfessionalInfoFormScreen>
     VoidCallback? onTap,
     IconData? suffixIcon,
     String? Function(String?)? validator,
+    List<TextInputFormatter>? inputFormatters,
   }) {
     if (config.isReadonly) {
       return FormFieldWrapper(
@@ -817,6 +816,7 @@ class _ProfessionalInfoFormScreenState extends State<ProfessionalInfoFormScreen>
         onTap: onTap,
         suffixIcon: suffixIcon,
         validator: validator,
+        inputFormatters: inputFormatters,
       );
     }
   }