feat: add active user session tracking and visualization in admin dashboard

as-talange-web/src/main/java/com/astalange/web/config/SecurityConfig.java

@@ -10,6 +10,9 @@ import org.springframework.security.config.annotation.web.configuration.EnableWe
 import org.springframework.security.crypto.argon2.Argon2PasswordEncoder;
 import org.springframework.security.crypto.password.PasswordEncoder;
 import org.springframework.security.web.SecurityFilterChain;
+import org.springframework.security.core.session.SessionRegistry;
+import org.springframework.security.core.session.SessionRegistryImpl;
+import org.springframework.security.web.session.HttpSessionEventPublisher;
 
 @Configuration
 @EnableWebSecurity
@@ -41,6 +44,10 @@ public class SecurityConfig {
             .logout(logout -> logout
                 .logoutSuccessUrl("/login?logout")
                 .permitAll()
+            )
+            .sessionManagement(session -> session
+                .maximumSessions(100)
+                .sessionRegistry(sessionRegistry())
             );
         return http.build();
     }
@@ -57,4 +64,14 @@ public class SecurityConfig {
         authProvider.setPasswordEncoder(passwordEncoder());
         return authProvider;
     }
+
+    @Bean
+    public SessionRegistry sessionRegistry() {
+        return new SessionRegistryImpl();
+    }
+
+    @Bean
+    public HttpSessionEventPublisher httpSessionEventPublisher() {
+        return new HttpSessionEventPublisher();
+    }
 }