feat(auth): restore authenticated user profile

eme-frontend/lib/screens/login_screen.dart

@@ -21,6 +21,14 @@ class LoginScreen extends StatefulWidget {
 class _LoginScreenState extends State<LoginScreen> {
   bool _connexionEnCours = false;
 
+  @override
+  void initState() {
+    super.initState();
+    if (AuthService.mode == AuthenticationMode.azure) {
+      WidgetsBinding.instance.addPostFrameCallback((_) => _restaurerSession());
+    }
+  }
+
   void _ouvrirEtudiant() {
     Navigator.of(context).push(
       MaterialPageRoute(
@@ -39,7 +47,44 @@ class _LoginScreenState extends State<LoginScreen> {
     );
   }
 
-  void _identifierParQr() {
+  void _ouvrirPourRole(String roleCode) {
+    switch (roleCode) {
+      case "ETUDIANT":
+        _ouvrirEtudiant();
+      case "RESPONSABLE":
+        _ouvrirResponsable();
+      default:
+        throw StateError("Role utilisateur non autorise.");
+    }
+  }
+
+  Future<void> _restaurerSession() async {
+    setState(() => _connexionEnCours = true);
+    try {
+      if (!await AuthService.hasMicrosoftAccount()) {
+        return;
+      }
+
+      final reponse = await ApiClient.get("/auth/me");
+      final profile = AuthService.setProfileFromApi(reponse);
+      if (mounted) {
+        _ouvrirPourRole(profile.roleCode);
+      }
+    } catch (_) {
+      if (!mounted) return;
+      ScaffoldMessenger.of(context).showSnackBar(
+        const SnackBar(
+          content: Text("La session Microsoft doit etre renouvelee."),
+        ),
+      );
+    } finally {
+      if (mounted) {
+        setState(() => _connexionEnCours = false);
+      }
+    }
+  }
+
+  Future<void> _identifierParQr() async {
     if (_connexionEnCours) return;
     if (AuthService.mode == AuthenticationMode.azure) {
       ScaffoldMessenger.of(context).showSnackBar(
@@ -52,8 +97,7 @@ class _LoginScreenState extends State<LoginScreen> {
       return;
     }
 
-    AuthService.selectDemoStudent();
-    _ouvrirEtudiant();
+    await _connecterMicrosoft(responsableDemo: false);
   }
 
   Future<void> _connecterMicrosoft({required bool responsableDemo}) async {
@@ -64,27 +108,17 @@ class _LoginScreenState extends State<LoginScreen> {
       if (AuthService.mode == AuthenticationMode.demo) {
         if (responsableDemo) {
           AuthService.selectDemoResponsable();
-          _ouvrirResponsable();
         } else {
           AuthService.selectDemoStudent();
-          _ouvrirEtudiant();
         }
-        return;
+      } else {
+        await AuthService.signInWithMicrosoft();
       }
 
-      await AuthService.signInWithMicrosoft();
       final reponse = await ApiClient.get("/auth/me");
-      final roleCode = _roleCode(reponse);
+      final profile = AuthService.setProfileFromApi(reponse);
       if (!mounted) return;
-
-      switch (roleCode) {
-        case "ETUDIANT":
-          _ouvrirEtudiant();
-        case "RESPONSABLE":
-          _ouvrirResponsable();
-        default:
-          throw StateError("Role utilisateur non autorise.");
-      }
+      _ouvrirPourRole(profile.roleCode);
     } catch (error) {
       if (!mounted) return;
       ScaffoldMessenger.of(
@@ -97,25 +131,6 @@ class _LoginScreenState extends State<LoginScreen> {
     }
   }
 
-  String _roleCode(dynamic reponse) {
-    if (reponse is! Map || reponse["data"] is! Map) {
-      throw StateError("Profil utilisateur invalide.");
-    }
-
-    final data = reponse["data"] as Map;
-    if (data["role"] is! Map) {
-      throw StateError("Role utilisateur absent.");
-    }
-
-    final role = data["role"] as Map;
-    final code = role["code"];
-    if (code is! String) {
-      throw StateError("Role utilisateur invalide.");
-    }
-
-    return code;
-  }
-
   @override
   Widget build(BuildContext context) {
     return Scaffold(