feat(auth): restore authenticated user profile

eme-frontend/lib/screens/responsable_screen.dart

@@ -1,7 +1,6 @@
 import "package:flutter/material.dart";
 import "package:google_fonts/google_fonts.dart";
 
-import "../demo_identity.dart";
 import "../services/auth_service.dart";
 import "../services/responsable_service.dart";
 import "../theme/ensup_colors.dart";
@@ -463,6 +462,12 @@ class _ResponsableTopBar extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final profile = AuthService.currentProfile;
+    final campusTag = profile?.campusTag ?? "Ensitech · Cergy";
+    final initials = profile?.initials ?? "KB";
+    final userName = profile?.fullName ?? "Karim Benali";
+    final roleLabel = profile?.roleLabel ?? "Responsable matériel";
+
     return Container(
       height: 68,
       padding: const EdgeInsets.symmetric(horizontal: 20),
@@ -533,7 +538,7 @@ class _ResponsableTopBar extends StatelessWidget {
                       ),
                       const SizedBox(width: 6),
                       Text(
-                        DemoIdentity.loginCampusTag,
+                        campusTag,
                         style: GoogleFonts.titilliumWeb(
                           fontSize: 12,
                           fontWeight: FontWeight.w600,
@@ -565,7 +570,7 @@ class _ResponsableTopBar extends StatelessWidget {
                   shape: BoxShape.circle,
                 ),
                 child: Text(
-                  "KB",
+                  initials,
                   style: GoogleFonts.darkerGrotesque(
                     color: Colors.white,
                     fontSize: 13,
@@ -580,7 +585,7 @@ class _ResponsableTopBar extends StatelessWidget {
                   crossAxisAlignment: CrossAxisAlignment.start,
                   children: [
                     Text(
-                      "Karim Benali",
+                      userName,
                       style: GoogleFonts.titilliumWeb(
                         fontSize: 13,
                         fontWeight: FontWeight.w700,
@@ -588,7 +593,7 @@ class _ResponsableTopBar extends StatelessWidget {
                       ),
                     ),
                     Text(
-                      "Responsable matériel",
+                      roleLabel,
                       style: GoogleFonts.titilliumWeb(
                         fontSize: 11,
                         color: EnsupColors.muted,