feat: Demo-Modus mit automatischer Session-Verwaltung und Rechnungsgenerator-Updates

2026-03-23 18:33:48 +01:00
parent b70c45b1d5
commit e949d0c46a
28 changed files with 1292 additions and 31 deletions
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 docker buildx build --platform linux/amd64 -t appcreationgmbh/votianlt:0.8.0 --push .

-docker buildx build --platform linux/amd64 -t repository.assecutor.de/votianlt:0.9.10 --push .
+docker buildx build --platform linux/amd64 -t registry.assecutor.de/votianlt:0.9.10 --push .

 adsg
 G8m0T3vz
--- a/src/main/bundles/dev.bundle
+++ b/src/main/bundles/dev.bundle
--- a/src/main/frontend/invoice-generator/profile-invoice-generator.js
+++ b/src/main/frontend/invoice-generator/profile-invoice-generator.js
@@ -165,6 +165,7 @@ window.initProfileInvoiceGenerator = function() {
    var w = (el.width || 100) * zoomFactor;
    var h = (el.height || 30) * zoomFactor;
    var fontSize = (el.fontSize || 14) * zoomFactor;
+    var textAlign = el.textAlign || 'left';
    
    if (el.type === 'line') {
      ctx.strokeStyle = el.color || '#333333';
@@ -269,9 +270,17 @@ window.initProfileInvoiceGenerator = function() {
      var fontWeight = (el.isStatic && !el.isCustomer) ? '' : (el.fontStyle || '');
      ctx.font = (fontWeight ? fontWeight + ' ' : '') + fontSize + 'px Arial';
      ctx.textBaseline = 'top';
+      ctx.textAlign = textAlign;
+
+      var textX = x;
+      if (textAlign === 'center') {
+        textX = x + (w / 2);
+      } else if (textAlign === 'right') {
+        textX = x + w;
+      }
      
      lines.forEach(function(line) {
-        ctx.fillText(line, x, ty);
+        ctx.fillText(line, textX, ty);
        ty += lineHeight;
      });
    }
@@ -1113,6 +1122,7 @@ window.initProfileInvoiceGenerator = function() {
        heightPercent: toPercentY(el.height),
        fontSize: el.fontSize,
        fontStyle: el.fontStyle,
+        textAlign: el.textAlign,
        color: el.color,
        isStatic: el.isStatic,
        isCustomer: el.isCustomer,
--- a/src/main/frontend/themes/votian-modern/styles.css
+++ b/src/main/frontend/themes/votian-modern/styles.css
@@ -361,7 +361,7 @@ vaadin-vertical-layout.admin-form-view {
 .hero-panel {
  position: relative;
  overflow: hidden;
-  min-height: 340px;
+  min-height: 420px;
  justify-content: center;
  text-align: center;
  border-radius: 34px;
@@ -430,6 +430,30 @@ vaadin-vertical-layout.admin-form-view {
  margin-top: 0.5rem;
 }

+.hero-actions {
+  gap: 1rem;
+  align-items: center;
+}
+
+.hero-action-group {
+  gap: 0.45rem;
+  align-items: center;
+}
+
+.hero-actions .hero-cta,
+.hero-actions .hero-demo-cta {
+  margin-top: 0;
+}
+
+.hero-choice-hint {
+  max-width: 420px;
+  margin: 0;
+  color: rgba(226, 232, 240, 0.82);
+  font-size: 0.95rem;
+  line-height: 1.55;
+  text-align: center;
+}
+
 .section-title {
  margin: 0;
  text-align: center;
--- a/src/main/java/de/assecutor/votianlt/config/DataInitializer.java
+++ b/src/main/java/de/assecutor/votianlt/config/DataInitializer.java
@@ -2,6 +2,7 @@ package de.assecutor.votianlt.config;

 import de.assecutor.votianlt.model.User;
 import de.assecutor.votianlt.repository.UserRepository;
+import de.assecutor.votianlt.service.DemoModeService;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.boot.CommandLineRunner;
@@ -18,15 +19,19 @@ public class DataInitializer implements CommandLineRunner {

    private final UserRepository userRepository;
    private final PasswordEncoder passwordEncoder;
+    private final DemoModeService demoModeService;

-    public DataInitializer(UserRepository userRepository, PasswordEncoder passwordEncoder) {
+    public DataInitializer(UserRepository userRepository, PasswordEncoder passwordEncoder,
+            DemoModeService demoModeService) {
        this.userRepository = userRepository;
        this.passwordEncoder = passwordEncoder;
+        this.demoModeService = demoModeService;
    }

    @Override
    public void run(String... args) throws Exception {
        initializeTestUsers();
+        demoModeService.ensureDemoUser();
    }

    private void initializeTestUsers() {
--- a/src/main/java/de/assecutor/votianlt/config/DemoSessionCleanupConfig.java
+++ b/src/main/java/de/assecutor/votianlt/config/DemoSessionCleanupConfig.java
@@ -0,0 +1,28 @@
+package de.assecutor.votianlt.config;
+
+import com.vaadin.flow.server.VaadinServiceInitListener;
+import de.assecutor.votianlt.service.DemoModeService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class DemoSessionCleanupConfig {
+
+    private static final Logger log = LoggerFactory.getLogger(DemoSessionCleanupConfig.class);
+
+    @Bean
+    public VaadinServiceInitListener demoSessionCleanupListener(DemoModeService demoModeService) {
+        return event -> event.getSource().addSessionDestroyListener(sessionDestroyEvent -> {
+            try {
+                var wrappedSession = sessionDestroyEvent.getSession().getSession();
+                if (wrappedSession != null) {
+                    demoModeService.cleanupAndReleaseIfOwned(wrappedSession.getId());
+                }
+            } catch (Exception ex) {
+                log.warn("Demo session destroy cleanup failed: {}", ex.getMessage(), ex);
+            }
+        });
+    }
+}
--- a/src/main/java/de/assecutor/votianlt/pages/view/JobSummaryView.java
+++ b/src/main/java/de/assecutor/votianlt/pages/view/JobSummaryView.java
@@ -522,7 +522,8 @@ public class JobSummaryView extends Main implements HasUrlParameter<String>, Has

    private List<String> buildDeliverySummaryDetails(List<BaseTask> tasks) {
        if (tasks == null || tasks.isEmpty()) {
-            return List.of(getTranslation("addjob.tab.tasks") + ": " + getTranslation("jobsummary.tasks.none"));
+            return new ArrayList<>(
+                    List.of(getTranslation("addjob.tab.tasks") + ": " + getTranslation("jobsummary.tasks.none")));
        }

        List<String> summaries = new ArrayList<>();
@@ -533,7 +534,8 @@ public class JobSummaryView extends Main implements HasUrlParameter<String>, Has
        }

        if (summaries.isEmpty()) {
-            return List.of(getTranslation("addjob.tab.tasks") + ": " + getTranslation("jobsummary.tasks.none"));
+            return new ArrayList<>(
+                    List.of(getTranslation("addjob.tab.tasks") + ": " + getTranslation("jobsummary.tasks.none")));
        }
        return summaries;
    }
@@ -651,7 +653,7 @@ public class JobSummaryView extends Main implements HasUrlParameter<String>, Has
            return sortVisibleTasks(station.getTasks());
        }

-        return List.of();
+        return new ArrayList<>();
    }

    private List<BaseTask> sortVisibleTasks(List<BaseTask> tasks) {
--- a/src/main/java/de/assecutor/votianlt/pages/view/LoginView.java
+++ b/src/main/java/de/assecutor/votianlt/pages/view/LoginView.java
@@ -21,13 +21,12 @@ import com.vaadin.flow.server.auth.AnonymousAllowed;
 import de.assecutor.votianlt.security.totp.TwoFactorService;
 import de.assecutor.votianlt.repository.UserRepository;
 import de.assecutor.votianlt.model.User;
+import de.assecutor.votianlt.security.SessionAuthenticationService;
+import de.assecutor.votianlt.service.DemoModeService;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.security.authentication.AuthenticationManager;
 import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
 import org.springframework.security.core.Authentication;
-import org.springframework.security.core.context.SecurityContextHolder;
-import org.springframework.security.web.context.HttpSessionSecurityContextRepository;
-import com.vaadin.flow.server.VaadinSession;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.core.env.Environment;
 import jakarta.annotation.PostConstruct;
@@ -53,6 +52,9 @@ public class LoginView extends VerticalLayout implements BeforeEnterObserver, Af
    @Autowired
    private UserRepository userRepository;

+    @Autowired
+    private SessionAuthenticationService sessionAuthenticationService;
+
    @Value("${app.security.two-factor.enabled:false}")
    private boolean twoFactorEnabledGlobal;

@@ -140,6 +142,15 @@ public class LoginView extends VerticalLayout implements BeforeEnterObserver, Af
    }

    private void handlePasswordLogin(String username, String password) {
+        hideInlineFlash();
+
+        if (DemoModeService.isDemoUsername(username)) {
+            pendingAuth = null;
+            loginForm.setError(true);
+            showInlineFlash(getTranslation("login.demo.only.button"));
+            return;
+        }
+
        try {
            // Prüfe Benutzername/Passwort
            Authentication auth = authenticationManager
@@ -158,13 +169,7 @@ public class LoginView extends VerticalLayout implements BeforeEnterObserver, Af
                Notification.show(getTranslation("login.2fa.sent"), 3000, Notification.Position.BOTTOM_CENTER);
            } else {
                // 2FA deaktiviert: Direkt anmelden
-                SecurityContextHolder.getContext().setAuthentication(auth);
-                var vaadinSession = VaadinSession.getCurrent();
-                if (vaadinSession != null) {
-                    var wrappedSession = vaadinSession.getSession();
-                    wrappedSession.setAttribute(HttpSessionSecurityContextRepository.SPRING_SECURITY_CONTEXT_KEY,
-                            SecurityContextHolder.getContext());
-                }
+                sessionAuthenticationService.storeAuthentication(auth);
                // Check if user is admin and redirect accordingly
                if (auth.getAuthorities().stream()
                        .anyMatch(authority -> authority.getAuthority().equals("ROLE_ADMIN"))) {
@@ -196,19 +201,12 @@ public class LoginView extends VerticalLayout implements BeforeEnterObserver, Af
            return;
        }
        // 2FA korrekt: Benutzer nun anmelden
-        SecurityContextHolder.getContext().setAuthentication(pendingAuth);
-        // Persistiere SecurityContext in der HTTP-Session, damit Vaadin/Security ihn in
-        // neuen Requests sieht
-        var vaadinSession = VaadinSession.getCurrent();
-        if (vaadinSession != null) {
-            var wrappedSession = vaadinSession.getSession();
-            wrappedSession.setAttribute(HttpSessionSecurityContextRepository.SPRING_SECURITY_CONTEXT_KEY,
-                    SecurityContextHolder.getContext());
-        }
+        Authentication authenticatedUser = pendingAuth;
+        sessionAuthenticationService.storeAuthentication(authenticatedUser);
        this.pendingAuth = null;
        // Full reload, damit der neue SecurityContext im UI sicher greift
        // Check if user is admin and redirect accordingly
-        if (SecurityContextHolder.getContext().getAuthentication().getAuthorities().stream()
+        if (authenticatedUser.getAuthorities().stream()
                .anyMatch(auth -> auth.getAuthority().equals("ROLE_ADMIN"))) {
            UI.getCurrent().getPage().setLocation("/admin-dashboard");
        } else {
@@ -246,4 +244,14 @@ public class LoginView extends VerticalLayout implements BeforeEnterObserver, Af
    public String getPageTitle() {
        return getTranslation("page.title.login");
    }
+
+    private void showInlineFlash(String message) {
+        flashBox.setText(message);
+        flashBox.getStyle().set("display", "block");
+    }
+
+    private void hideInlineFlash() {
+        flashBox.setText("");
+        flashBox.getStyle().set("display", "none");
+    }
 }
--- a/src/main/java/de/assecutor/votianlt/pages/view/StartView.java
+++ b/src/main/java/de/assecutor/votianlt/pages/view/StartView.java
@@ -9,6 +9,8 @@ import com.vaadin.flow.component.contextmenu.ContextMenu;
 import com.vaadin.flow.component.html.*;
 import com.vaadin.flow.component.icon.Icon;
 import com.vaadin.flow.component.icon.VaadinIcon;
+import com.vaadin.flow.component.notification.Notification;
+import com.vaadin.flow.component.notification.NotificationVariant;
 import com.vaadin.flow.component.orderedlayout.FlexComponent;
 import com.vaadin.flow.component.orderedlayout.HorizontalLayout;
 import com.vaadin.flow.component.orderedlayout.VerticalLayout;
@@ -18,8 +20,12 @@ import com.vaadin.flow.router.BeforeEnterEvent;
 import com.vaadin.flow.router.BeforeEnterObserver;
 import com.vaadin.flow.server.auth.AnonymousAllowed;
 import de.assecutor.votianlt.model.Language;
+import de.assecutor.votianlt.security.SessionAuthenticationService;
 import de.assecutor.votianlt.security.SecurityService;
+import de.assecutor.votianlt.service.DemoModeService;
 import org.springframework.beans.factory.annotation.Value;
+import org.springframework.security.authentication.AuthenticationManager;
+import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;

 import java.util.Locale;

@@ -28,10 +34,18 @@ import java.util.Locale;
 public class StartView extends VerticalLayout implements BeforeEnterObserver, HasDynamicTitle {

    private final SecurityService securityService;
+    private final DemoModeService demoModeService;
+    private final SessionAuthenticationService sessionAuthenticationService;
+    private final AuthenticationManager authenticationManager;
    private final String appVersion;

-    public StartView(SecurityService securityService, @Value("${app.version:unknown}") String appVersion) {
+    public StartView(SecurityService securityService, DemoModeService demoModeService,
+            SessionAuthenticationService sessionAuthenticationService, AuthenticationManager authenticationManager,
+            @Value("${app.version:unknown}") String appVersion) {
        this.securityService = securityService;
+        this.demoModeService = demoModeService;
+        this.sessionAuthenticationService = sessionAuthenticationService;
+        this.authenticationManager = authenticationManager;
        this.appVersion = appVersion;
        addClassName("landing-view");
        setSizeFull();
@@ -278,11 +292,48 @@ public class StartView extends VerticalLayout implements BeforeEnterObserver, Ha
        Paragraph heroDescription = new Paragraph(getTranslation("start.hero.description"));
        heroDescription.addClassName("hero-panel-text");

+        Button demoButton = new Button(getTranslation("start.button.demo"), event -> loginDemo());
+        demoButton.addThemeVariants(ButtonVariant.LUMO_PRIMARY, ButtonVariant.LUMO_LARGE);
+        demoButton.addClassNames("hero-cta", "hero-demo-cta");
+        demoButton.setWidthFull();
+
        Button ctaButton = new Button(getTranslation("cta.freetest"), event -> register());
        ctaButton.addThemeVariants(ButtonVariant.LUMO_PRIMARY, ButtonVariant.LUMO_LARGE);
        ctaButton.addClassName("hero-cta");
+        ctaButton.setWidthFull();

-        heroSection.add(heroIcon, heroTitle, heroDescription, ctaButton);
+        Paragraph demoHint = new Paragraph(getTranslation("start.hero.demo.hint"));
+        demoHint.addClassName("hero-choice-hint");
+
+        Paragraph trialHint = new Paragraph(getTranslation("start.hero.trial.hint"));
+        trialHint.addClassName("hero-choice-hint");
+
+        VerticalLayout demoAction = new VerticalLayout();
+        demoAction.setPadding(false);
+        demoAction.setSpacing(false);
+        demoAction.setWidthFull();
+        demoAction.setDefaultHorizontalComponentAlignment(FlexComponent.Alignment.CENTER);
+        demoAction.addClassName("hero-action-group");
+        demoAction.add(demoButton, demoHint);
+
+        VerticalLayout trialAction = new VerticalLayout();
+        trialAction.setPadding(false);
+        trialAction.setSpacing(false);
+        trialAction.setWidthFull();
+        trialAction.setDefaultHorizontalComponentAlignment(FlexComponent.Alignment.CENTER);
+        trialAction.addClassName("hero-action-group");
+        trialAction.add(ctaButton, trialHint);
+
+        VerticalLayout heroActions = new VerticalLayout();
+        heroActions.setPadding(false);
+        heroActions.setSpacing(false);
+        heroActions.setWidthFull();
+        heroActions.setMaxWidth("420px");
+        heroActions.setDefaultHorizontalComponentAlignment(FlexComponent.Alignment.CENTER);
+        heroActions.addClassName("hero-actions");
+        heroActions.add(demoAction, trialAction);
+
+        heroSection.add(heroIcon, heroTitle, heroDescription, heroActions);
        return heroSection;
    }

@@ -407,6 +458,38 @@ public class StartView extends VerticalLayout implements BeforeEnterObserver, Ha
        UI.getCurrent().navigate("login");
    }

+    private void loginDemo() {
+        String sessionId = sessionAuthenticationService.getCurrentSessionId().orElse(null);
+        if (sessionId == null) {
+            showDemoNotification(getTranslation("demo.start.error"), NotificationVariant.LUMO_ERROR);
+            return;
+        }
+
+        boolean prepared = false;
+        try {
+            prepared = demoModeService.tryPrepareDemoSession(sessionId);
+            if (!prepared) {
+                showDemoNotification(getTranslation("demo.session.active"), NotificationVariant.LUMO_ERROR);
+                return;
+            }
+
+            var auth = authenticationManager.authenticate(
+                    new UsernamePasswordAuthenticationToken(DemoModeService.DEMO_USERNAME, DemoModeService.DEMO_PASSWORD));
+            sessionAuthenticationService.storeAuthentication(auth);
+            UI.getCurrent().getPage().setLocation("/dashboard");
+        } catch (Exception ex) {
+            if (prepared) {
+                demoModeService.cleanupAndReleaseIfOwned(sessionId);
+            }
+            showDemoNotification(getTranslation("demo.start.error"), NotificationVariant.LUMO_ERROR);
+        }
+    }
+
+    private void showDemoNotification(String message, NotificationVariant variant) {
+        Notification notification = Notification.show(message, 4000, Notification.Position.TOP_CENTER);
+        notification.addThemeVariants(variant);
+    }
+
    @Override
    public String getPageTitle() {
        return getTranslation("page.title.welcome");
--- a/src/main/java/de/assecutor/votianlt/pages/view/UserMessagesView.java
+++ b/src/main/java/de/assecutor/votianlt/pages/view/UserMessagesView.java
@@ -2,7 +2,6 @@ package de.assecutor.votianlt.pages.view;

 import com.vaadin.flow.component.UI;
 import com.vaadin.flow.component.html.Div;
-import com.vaadin.flow.component.html.H2;
 import com.vaadin.flow.component.html.H3;
 import com.vaadin.flow.component.html.Main;
 import com.vaadin.flow.component.html.Span;
--- a/src/main/java/de/assecutor/votianlt/security/SecurityService.java
+++ b/src/main/java/de/assecutor/votianlt/security/SecurityService.java
@@ -1,6 +1,8 @@
 package de.assecutor.votianlt.security;

 import com.vaadin.flow.spring.security.AuthenticationContext;
+import de.assecutor.votianlt.service.DemoModeService;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.core.context.SecurityContextHolder;
 import org.springframework.security.authentication.AnonymousAuthenticationToken;
@@ -12,12 +14,15 @@ import org.springframework.stereotype.Component;
 import java.util.Optional;

@Component
+@Slf4j
 public class SecurityService {

    private final AuthenticationContext authenticationContext;
+    private final DemoModeService demoModeService;

-    public SecurityService(AuthenticationContext authenticationContext) {
+    public SecurityService(AuthenticationContext authenticationContext, DemoModeService demoModeService) {
        this.authenticationContext = authenticationContext;
+        this.demoModeService = demoModeService;
    }

    public Optional<UserDetails> getAuthenticatedUser() {
@@ -99,6 +104,14 @@ public class SecurityService {
    }

    public void logout() {
+        try {
+            String authenticatedUsername = getAuthenticatedUser().map(UserDetails::getUsername).orElse(null);
+            if (DemoModeService.isDemoUsername(authenticatedUsername)) {
+                demoModeService.cleanupCurrentSessionIfOwned();
+            }
+        } catch (Exception ex) {
+            log.warn("Demo logout cleanup failed: {}", ex.getMessage(), ex);
+        }
        authenticationContext.logout();
    }

--- a/src/main/java/de/assecutor/votianlt/security/SessionAuthenticationService.java
+++ b/src/main/java/de/assecutor/votianlt/security/SessionAuthenticationService.java
@@ -0,0 +1,37 @@
+package de.assecutor.votianlt.security;
+
+import com.vaadin.flow.server.VaadinSession;
+import java.util.Optional;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.context.SecurityContextHolder;
+import org.springframework.security.web.context.HttpSessionSecurityContextRepository;
+import org.springframework.stereotype.Service;
+
+@Service
+public class SessionAuthenticationService {
+
+    public void storeAuthentication(Authentication authentication) {
+        SecurityContextHolder.getContext().setAuthentication(authentication);
+
+        VaadinSession vaadinSession = VaadinSession.getCurrent();
+        if (vaadinSession == null) {
+            return;
+        }
+
+        var wrappedSession = vaadinSession.getSession();
+        if (wrappedSession == null) {
+            return;
+        }
+
+        wrappedSession.setAttribute(HttpSessionSecurityContextRepository.SPRING_SECURITY_CONTEXT_KEY,
+                SecurityContextHolder.getContext());
+    }
+
+    public Optional<String> getCurrentSessionId() {
+        VaadinSession vaadinSession = VaadinSession.getCurrent();
+        if (vaadinSession == null || vaadinSession.getSession() == null) {
+            return Optional.empty();
+        }
+        return Optional.ofNullable(vaadinSession.getSession().getId());
+    }
+}
--- a/src/main/java/de/assecutor/votianlt/service/CustomerInvoiceService.java
+++ b/src/main/java/de/assecutor/votianlt/service/CustomerInvoiceService.java
@@ -358,6 +358,7 @@ public class CustomerInvoiceService {

                int fontSize = element.has("fontSize") ? element.get("fontSize").asInt(14) : 14;
                String color = element.has("color") ? element.get("color").asText("#333333") : "#333333";
+                String textAlign = element.has("textAlign") ? element.get("textAlign").asText("left") : "left";

                // Convert percentages to mm (A4 is 210mm x 297mm)
                double mmX = xPercent / 100.0 * 210.0;
@@ -392,6 +393,17 @@ public class CustomerInvoiceService {
                    } else {
                        // Vertically center content for other elements
                        htmlBuilder.append("display:flex;align-items:center;");
+                        switch (textAlign) {
+                        case "center":
+                            htmlBuilder.append("justify-content:center;text-align:center;");
+                            break;
+                        case "right":
+                            htmlBuilder.append("justify-content:flex-end;text-align:right;");
+                            break;
+                        default:
+                            htmlBuilder.append("justify-content:flex-start;text-align:left;");
+                            break;
+                        }
                    }
                }
                htmlBuilder.append("'");
@@ -649,6 +661,7 @@ public class CustomerInvoiceService {

                int fontSize = element.has("fontSize") ? element.get("fontSize").asInt(14) : 14;
                String color = element.has("color") ? element.get("color").asText("#333333") : "#333333";
+                String textAlign = element.has("textAlign") ? element.get("textAlign").asText("left") : "left";

                // Convert percentages to mm (A4 is 210mm x 297mm)
                double mmX = xPercent / 100.0 * 210.0;
@@ -682,6 +695,17 @@ public class CustomerInvoiceService {
                        htmlBuilder.append("display:block;overflow:visible;padding:0;");
                    } else {
                        htmlBuilder.append("display:flex;align-items:center;");
+                        switch (textAlign) {
+                        case "center":
+                            htmlBuilder.append("justify-content:center;text-align:center;");
+                            break;
+                        case "right":
+                            htmlBuilder.append("justify-content:flex-end;text-align:right;");
+                            break;
+                        default:
+                            htmlBuilder.append("justify-content:flex-start;text-align:left;");
+                            break;
+                        }
                    }
                }
                htmlBuilder.append("'");
--- a/src/main/java/de/assecutor/votianlt/service/DemoModeService.java
+++ b/src/main/java/de/assecutor/votianlt/service/DemoModeService.java
@@ -0,0 +1,547 @@
+package de.assecutor.votianlt.service;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import de.assecutor.votianlt.model.AppUser;
+import de.assecutor.votianlt.model.Barcode;
+import de.assecutor.votianlt.model.Comment;
+import de.assecutor.votianlt.model.Customer;
+import de.assecutor.votianlt.model.DeliveryStation;
+import de.assecutor.votianlt.model.InvoiceTemplate;
+import de.assecutor.votianlt.model.Job;
+import de.assecutor.votianlt.model.JobServiceSelection;
+import de.assecutor.votianlt.model.JobStatus;
+import de.assecutor.votianlt.model.Language;
+import de.assecutor.votianlt.model.LocationPosition;
+import de.assecutor.votianlt.model.Photo;
+import de.assecutor.votianlt.model.Service;
+import de.assecutor.votianlt.model.Signature;
+import de.assecutor.votianlt.model.TaskTemplate;
+import de.assecutor.votianlt.model.User;
+import de.assecutor.votianlt.model.invoices.CustomerInvoice;
+import de.assecutor.votianlt.model.task.BaseTask;
+import de.assecutor.votianlt.pages.domain.CustomerRepository;
+import de.assecutor.votianlt.repository.AppUserRepository;
+import de.assecutor.votianlt.repository.BarcodeRepository;
+import de.assecutor.votianlt.repository.CargoItemRepository;
+import de.assecutor.votianlt.repository.CommentRepository;
+import de.assecutor.votianlt.repository.CustomerInvoiceRepository;
+import de.assecutor.votianlt.repository.InvoiceTemplateRepository;
+import de.assecutor.votianlt.repository.JobHistoryRepository;
+import de.assecutor.votianlt.repository.JobRepository;
+import de.assecutor.votianlt.repository.LocationPositionRepository;
+import de.assecutor.votianlt.repository.MessageRepository;
+import de.assecutor.votianlt.repository.PhotoRepository;
+import de.assecutor.votianlt.repository.ServiceRepository;
+import de.assecutor.votianlt.repository.SignatureRepository;
+import de.assecutor.votianlt.repository.TaskRepository;
+import de.assecutor.votianlt.repository.TaskTemplateRepository;
+import de.assecutor.votianlt.repository.UserInvoiceDataRepository;
+import de.assecutor.votianlt.repository.UserRepository;
+import de.assecutor.votianlt.security.SessionAuthenticationService;
+import java.io.IOException;
+import java.math.BigDecimal;
+import java.nio.charset.StandardCharsets;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.time.LocalTime;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.bson.types.ObjectId;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.security.crypto.password.PasswordEncoder;
+import org.springframework.transaction.annotation.Transactional;
+
+@org.springframework.stereotype.Service
+@RequiredArgsConstructor
+@Transactional
+@Slf4j
+public class DemoModeService {
+
+    public static final String DEMO_USERNAME = "demo";
+    public static final String DEMO_PASSWORD = "demo";
+    private static final String DEMO_FIRST_NAME = "Demo";
+    private static final String DEMO_LAST_NAME = "Benutzer";
+    private static final String DEMO_INVOICE_TEMPLATE_RESOURCE = "templates/demo_invoice_template_default.json";
+
+    private final DemoSessionRegistry demoSessionRegistry;
+    private final SessionAuthenticationService sessionAuthenticationService;
+    private final UserRepository userRepository;
+    private final CustomerRepository customerRepository;
+    private final JobRepository jobRepository;
+    private final CargoItemRepository cargoItemRepository;
+    private final TaskRepository taskRepository;
+    private final JobHistoryRepository jobHistoryRepository;
+    private final CustomerInvoiceRepository customerInvoiceRepository;
+    private final ServiceRepository serviceRepository;
+    private final AppUserRepository appUserRepository;
+    private final TaskTemplateRepository taskTemplateRepository;
+    private final InvoiceTemplateRepository invoiceTemplateRepository;
+    private final UserInvoiceDataRepository userInvoiceDataRepository;
+    private final MessageRepository messageRepository;
+    private final LocationPositionRepository locationPositionRepository;
+    private final PhotoRepository photoRepository;
+    private final SignatureRepository signatureRepository;
+    private final BarcodeRepository barcodeRepository;
+    private final CommentRepository commentRepository;
+    private final PasswordEncoder passwordEncoder;
+
+    public static boolean isDemoUsername(String username) {
+        return username != null && DEMO_USERNAME.equalsIgnoreCase(username.trim());
+    }
+
+    public void ensureDemoUser() {
+        User demoUser = userRepository.findByEmail(DEMO_USERNAME).orElseGet(User::new);
+        applyDemoUserDefaults(demoUser);
+        userRepository.save(demoUser);
+    }
+
+    public boolean tryPrepareDemoSession(String sessionId) {
+        if (!demoSessionRegistry.acquire(sessionId)) {
+            return false;
+        }
+
+        try {
+            ensureDemoUser();
+            cleanupDemoOwnedData();
+            resetDemoUserProfile();
+            seedDemoData();
+            return true;
+        } catch (RuntimeException ex) {
+            demoSessionRegistry.release(sessionId);
+            throw ex;
+        }
+    }
+
+    public void cleanupCurrentSessionIfOwned() {
+        sessionAuthenticationService.getCurrentSessionId().ifPresent(this::cleanupAndReleaseIfOwned);
+    }
+
+    public void cleanupAndReleaseIfOwned(String sessionId) {
+        if (!demoSessionRegistry.isHeldBy(sessionId)) {
+            return;
+        }
+
+        try {
+            cleanupDemoOwnedData();
+            resetDemoUserProfile();
+        } catch (RuntimeException ex) {
+            log.warn("Demo cleanup failed for session {}: {}", sessionId, ex.getMessage(), ex);
+        } finally {
+            demoSessionRegistry.release(sessionId);
+        }
+    }
+
+    public void resetDemoUserProfile() {
+        User demoUser = getDemoUser();
+        applyDemoUserDefaults(demoUser);
+        userRepository.save(demoUser);
+    }
+
+    public void cleanupDemoOwnedData() {
+        Optional<User> demoUserOptional = userRepository.findByEmail(DEMO_USERNAME);
+        if (demoUserOptional.isEmpty()) {
+            return;
+        }
+
+        User demoUser = demoUserOptional.get();
+        ObjectId demoUserId = demoUser.getId();
+        if (demoUserId == null) {
+            return;
+        }
+
+        String demoUserIdHex = demoUserId.toHexString();
+
+        List<AppUser> demoAppUsers = appUserRepository.findByErstelltVon(demoUserId);
+        cleanupDemoAppUserData(demoAppUsers);
+
+        List<Job> demoJobs = jobRepository.findByCreatedBy(demoUserIdHex);
+        cleanupDemoJobData(demoJobs);
+
+        List<Customer> demoCustomers = customerRepository.findByOwner(demoUserId);
+        if (!demoCustomers.isEmpty()) {
+            customerRepository.deleteAll(demoCustomers);
+        }
+
+        serviceRepository.deleteByUserId(demoUserIdHex);
+
+        List<TaskTemplate> demoTaskTemplates = taskTemplateRepository.findByUserIdOrderByTemplateNameAsc(demoUserId);
+        if (!demoTaskTemplates.isEmpty()) {
+            taskTemplateRepository.deleteAll(demoTaskTemplates);
+        }
+
+        invoiceTemplateRepository.deleteByUserId(demoUserIdHex);
+        userInvoiceDataRepository.deleteByUserId(demoUserId);
+
+        List<CustomerInvoice> demoInvoices = customerInvoiceRepository.findByUserId(demoUserIdHex);
+        if (!demoInvoices.isEmpty()) {
+            customerInvoiceRepository.deleteAll(demoInvoices);
+        }
+
+        if (!demoAppUsers.isEmpty()) {
+            appUserRepository.deleteAll(demoAppUsers);
+        }
+    }
+
+    public void seedDemoData() {
+        User demoUser = getDemoUser();
+        List<Service> services = seedDemoServices(demoUser);
+        List<Customer> customers = seedDemoCustomers(demoUser);
+        seedDemoJobs(demoUser, customers, services);
+        seedDemoInvoiceTemplate(demoUser);
+    }
+
+    private void cleanupDemoAppUserData(List<AppUser> demoAppUsers) {
+        for (AppUser appUser : demoAppUsers) {
+            String appUserId = appUser.getIdAsString();
+            if (appUserId == null || appUserId.isBlank()) {
+                continue;
+            }
+
+            var messages = messageRepository.findByReceiverOrderByCreatedAtAsc(appUserId);
+            if (!messages.isEmpty()) {
+                messageRepository.deleteAll(messages);
+            }
+
+            var positions = locationPositionRepository.findByAppUserIdOrderByTimestampDesc(appUserId);
+            if (!positions.isEmpty()) {
+                locationPositionRepository.deleteAll(positions);
+            }
+        }
+    }
+
+    private void cleanupDemoJobData(List<Job> demoJobs) {
+        if (demoJobs.isEmpty()) {
+            return;
+        }
+
+        Set<ObjectId> stationIds = new LinkedHashSet<>();
+        Set<ObjectId> jobIds = new LinkedHashSet<>();
+        Set<String> jobIdStrings = new LinkedHashSet<>();
+        for (Job job : demoJobs) {
+            if (job == null || job.getId() == null) {
+                continue;
+            }
+            jobIds.add(job.getId());
+            jobIdStrings.add(job.getIdAsString());
+            if (job.getDeliveryStations() == null) {
+                continue;
+            }
+            for (DeliveryStation station : job.getDeliveryStations()) {
+                if (station != null && station.getStationId() != null) {
+                    stationIds.add(station.getStationId());
+                }
+            }
+        }
+
+        Map<ObjectId, BaseTask> tasksById = new LinkedHashMap<>();
+        if (!stationIds.isEmpty()) {
+            for (BaseTask task : taskRepository.findByStationIdIn(new ArrayList<>(stationIds))) {
+                if (task != null && task.getId() != null) {
+                    tasksById.put(task.getId(), task);
+                }
+            }
+        }
+        for (ObjectId jobId : jobIds) {
+            for (BaseTask task : taskRepository.findByJobIdOrderByTaskOrderAsc(jobId)) {
+                if (task != null && task.getId() != null) {
+                    tasksById.put(task.getId(), task);
+                }
+            }
+        }
+
+        cleanupTaskArtifacts(tasksById.keySet());
+
+        if (!tasksById.isEmpty()) {
+            taskRepository.deleteAll(tasksById.values());
+        }
+
+        for (ObjectId jobId : jobIds) {
+            var cargoItems = cargoItemRepository.findByJobId(jobId);
+            if (!cargoItems.isEmpty()) {
+                cargoItemRepository.deleteAll(cargoItems);
+            }
+            jobHistoryRepository.deleteByJobId(jobId);
+        }
+
+        List<CustomerInvoice> invoicesToDelete = new ArrayList<>();
+        for (String jobId : jobIdStrings) {
+            customerInvoiceRepository.findByJobId(jobId).ifPresent(invoicesToDelete::add);
+        }
+        if (!invoicesToDelete.isEmpty()) {
+            customerInvoiceRepository.deleteAll(dedupeInvoices(invoicesToDelete));
+        }
+
+        jobRepository.deleteAll(demoJobs);
+    }
+
+    private void cleanupTaskArtifacts(Collection<ObjectId> taskIds) {
+        for (ObjectId taskId : taskIds) {
+            if (taskId == null) {
+                continue;
+            }
+
+            List<Photo> photos = photoRepository.findByTaskId(taskId);
+            if (!photos.isEmpty()) {
+                photoRepository.deleteAll(photos);
+            }
+
+            List<Signature> signatures = signatureRepository.findByTaskId(taskId);
+            if (!signatures.isEmpty()) {
+                signatureRepository.deleteAll(signatures);
+            }
+
+            List<Barcode> barcodes = barcodeRepository.findByTaskId(taskId);
+            if (!barcodes.isEmpty()) {
+                barcodeRepository.deleteAll(barcodes);
+            }
+
+            List<Comment> comments = commentRepository.findByTaskIdOrderByCreatedAtDesc(taskId);
+            if (!comments.isEmpty()) {
+                commentRepository.deleteAll(comments);
+            }
+        }
+    }
+
+    private List<CustomerInvoice> dedupeInvoices(List<CustomerInvoice> invoices) {
+        Map<String, CustomerInvoice> unique = new LinkedHashMap<>();
+        for (CustomerInvoice invoice : invoices) {
+            if (invoice == null || invoice.getId() == null) {
+                continue;
+            }
+            unique.putIfAbsent(invoice.getId(), invoice);
+        }
+        return new ArrayList<>(unique.values());
+    }
+
+    private List<Customer> seedDemoCustomers(User demoUser) {
+        ObjectId demoUserId = demoUser.getId();
+
+        Customer firstCustomer = new Customer();
+        firstCustomer.setTitle("Frau");
+        firstCustomer.setCompanyName("Demo Bau GmbH");
+        firstCustomer.setFirstname("Anna");
+        firstCustomer.setLastName("Sommer");
+        firstCustomer.setTelephone("030 1234567");
+        firstCustomer.setMail("anna.sommer@demo.invalid");
+        firstCustomer.setStreet("Musterstrasse");
+        firstCustomer.setHouseNumber("12");
+        firstCustomer.setZip("10115");
+        firstCustomer.setCity("Berlin");
+        firstCustomer.setCreatedBy(demoUserId);
+        firstCustomer.setOwner(demoUserId);
+
+        Customer secondCustomer = new Customer();
+        secondCustomer.setTitle("Herr");
+        secondCustomer.setCompanyName("Nordhandel AG");
+        secondCustomer.setFirstname("Lukas");
+        secondCustomer.setLastName("Becker");
+        secondCustomer.setTelephone("040 7654321");
+        secondCustomer.setMail("lukas.becker@demo.invalid");
+        secondCustomer.setStreet("Hafenallee");
+        secondCustomer.setHouseNumber("8");
+        secondCustomer.setZip("20095");
+        secondCustomer.setCity("Hamburg");
+        secondCustomer.setCreatedBy(demoUserId);
+        secondCustomer.setOwner(demoUserId);
+
+        return customerRepository.saveAll(List.of(firstCustomer, secondCustomer));
+    }
+
+    private List<Service> seedDemoServices(User demoUser) {
+        String demoUserId = demoUser.getId().toHexString();
+
+        Service activeService = createFlatRateService(demoUserId, "Expresszustellung", "149.00");
+        Service completedService = createFlatRateService(demoUserId, "Konsolidierungszustellung", "219.00");
+
+        return serviceRepository.saveAll(List.of(activeService, completedService));
+    }
+
+    private void seedDemoJobs(User demoUser, List<Customer> customers, List<Service> services) {
+        Map<String, Customer> customersByCompany = new LinkedHashMap<>();
+        for (Customer customer : customers) {
+            customersByCompany.put(customer.getCompanyName(), customer);
+        }
+        Map<String, Service> servicesByName = new LinkedHashMap<>();
+        for (Service service : services) {
+            servicesByName.put(service.getName(), service);
+        }
+
+        LocalDateTime now = LocalDateTime.now();
+        String demoUserId = demoUser.getId().toHexString();
+
+        Job activeJob = new Job();
+        activeJob.setJobNumber("DEMO-AKTIV-001");
+        activeJob.setStatus(JobStatus.IN_PROGRESS);
+        activeJob.setCreatedAt(now.minusDays(2));
+        activeJob.setUpdatedAt(now.minusHours(3));
+        activeJob.setCreatedBy(demoUserId);
+        activeJob.setDraft(false);
+        activeJob.setDigitalProcessing(false);
+        activeJob.setPickupDate(LocalDate.now().minusDays(1));
+        activeJob.setPickupTime(LocalTime.of(9, 30));
+        activeJob.setRemark("Demo-Auftrag aktiv");
+        activeJob.setPrice(new BigDecimal("149.00"));
+        applyCustomerToPickup(activeJob, customersByCompany.get("Demo Bau GmbH"));
+        activeJob.setCustomerSelection("Demo Bau GmbH | Anna Sommer");
+        activeJob.setDeliveryStations(new ArrayList<>(List.of(
+                createDeliveryStation("Potsdam Expresslager", "Herr", "Timo", "Kranz", "0331 444555",
+                        "Lange Bruecke", "4", null, "14467", "Potsdam", LocalDate.now(), LocalTime.of(14, 0), 0))));
+        activeJob.setServiceIds(new ArrayList<>(List.of(servicesByName.get("Expresszustellung").getId())));
+        activeJob.setSelectedServices(new ArrayList<>(List.of(
+                createJobServiceSelection(servicesByName.get("Expresszustellung"), 0))));
+        activeJob.syncFlatDeliveryFieldsFromStations();
+
+        Job completedJob = new Job();
+        completedJob.setJobNumber("DEMO-ERLEDIGT-001");
+        completedJob.setStatus(JobStatus.COMPLETED);
+        completedJob.setCreatedAt(now.minusDays(8));
+        completedJob.setUpdatedAt(now.minusDays(5));
+        completedJob.setCreatedBy(demoUserId);
+        completedJob.setDraft(false);
+        completedJob.setDigitalProcessing(false);
+        completedJob.setPickupDate(LocalDate.now().minusDays(7));
+        completedJob.setPickupTime(LocalTime.of(8, 15));
+        completedJob.setRemark("Demo-Auftrag abgeschlossen");
+        completedJob.setPrice(new BigDecimal("219.00"));
+        applyCustomerToPickup(completedJob, customersByCompany.get("Nordhandel AG"));
+        completedJob.setCustomerSelection("Nordhandel AG | Lukas Becker");
+        completedJob.setDeliveryStations(new ArrayList<>(List.of(
+                createDeliveryStation("Bremen Konsolidierung", "Frau", "Mara", "Jensen", "0421 987654", "Kontorweg",
+                        "19", null, "28195", "Bremen", LocalDate.now().minusDays(6), LocalTime.of(16, 30), 0))));
+        completedJob.setServiceIds(new ArrayList<>(List.of(servicesByName.get("Konsolidierungszustellung").getId())));
+        completedJob.setSelectedServices(new ArrayList<>(List.of(
+                createJobServiceSelection(servicesByName.get("Konsolidierungszustellung"), 0))));
+        completedJob.syncFlatDeliveryFieldsFromStations();
+
+        jobRepository.saveAll(List.of(activeJob, completedJob));
+    }
+
+    private Service createFlatRateService(String userId, String name, String price) {
+        Service service = new Service();
+        service.setId(new ObjectId().toHexString());
+        service.setUserId(userId);
+        service.setName(name);
+        service.setCalculationBasis(Service.CalculationBasis.FLAT_RATE);
+        service.setPrice(new BigDecimal(price));
+        service.setMandatory(false);
+        return service;
+    }
+
+    private JobServiceSelection createJobServiceSelection(Service service, int deliveryStationOrder) {
+        JobServiceSelection selection = new JobServiceSelection();
+        selection.setServiceId(service.getId());
+        selection.setDeliveryStationOrder(deliveryStationOrder);
+        return selection;
+    }
+
+    private void seedDemoInvoiceTemplate(User demoUser) {
+        InvoiceTemplate template = new InvoiceTemplate(demoUser.getId().toHexString(), "Einfach",
+                createDemoInvoiceTemplateData());
+        invoiceTemplateRepository.save(template);
+    }
+
+    private String createDemoInvoiceTemplateData() {
+        try {
+            String templateJson = new String(
+                    new ClassPathResource(DEMO_INVOICE_TEMPLATE_RESOURCE).getInputStream().readAllBytes(),
+                    StandardCharsets.UTF_8);
+            return new ObjectMapper().writeValueAsString(templateJson);
+        } catch (IOException ex) {
+            throw new IllegalStateException("Could not load demo invoice template", ex);
+        }
+    }
+
+    private void applyCustomerToPickup(Job job, Customer customer) {
+        if (job == null || customer == null) {
+            return;
+        }
+        job.setPickupCompany(customer.getCompanyName());
+        job.setPickupSalutation(customer.getTitle());
+        job.setPickupFirstName(customer.getFirstname());
+        job.setPickupLastName(customer.getLastName());
+        job.setPickupPhone(customer.getTelephone());
+        job.setPickupStreet(customer.getStreet());
+        job.setPickupHouseNumber(customer.getHouseNumber());
+        job.setPickupAddressAddition(customer.getAddressAddition());
+        job.setPickupZip(customer.getZip());
+        job.setPickupCity(customer.getCity());
+    }
+
+    private DeliveryStation createDeliveryStation(String company, String salutation, String firstName, String lastName,
+            String phone, String street, String houseNumber, String addressAddition, String zip, String city,
+            LocalDate deliveryDate, LocalTime deliveryTime, int stationOrder) {
+        DeliveryStation station = new DeliveryStation();
+        station.ensureStationId();
+        station.setStationOrder(stationOrder);
+        station.setCompany(company);
+        station.setSalutation(salutation);
+        station.setFirstName(firstName);
+        station.setLastName(lastName);
+        station.setPhone(phone);
+        station.setStreet(street);
+        station.setHouseNumber(houseNumber);
+        station.setAddressAddition(addressAddition);
+        station.setZip(zip);
+        station.setCity(city);
+        station.setDeliveryDate(deliveryDate);
+        station.setDeliveryTime(deliveryTime);
+        station.setTasks(new ArrayList<>());
+        return station;
+    }
+
+    private User getDemoUser() {
+        return userRepository.findByEmail(DEMO_USERNAME)
+                .orElseThrow(() -> new IllegalStateException("Demo user does not exist"));
+    }
+
+    private void applyDemoUserDefaults(User demoUser) {
+        LocalDateTime now = LocalDateTime.now();
+        if (demoUser.getCreatedAt() == null) {
+            demoUser.setCreatedAt(now);
+        }
+
+        demoUser.setEmail(DEMO_USERNAME);
+        demoUser.setPassword(passwordEncoder.encode(DEMO_PASSWORD));
+        demoUser.setFirstname(DEMO_FIRST_NAME);
+        demoUser.setName(DEMO_LAST_NAME);
+        demoUser.setTitle(null);
+        demoUser.setCompany(null);
+        demoUser.setCompanyAddition(null);
+        demoUser.setStreet(null);
+        demoUser.setHouseNumber(null);
+        demoUser.setAddressAddition(null);
+        demoUser.setZip(null);
+        demoUser.setCity(null);
+        demoUser.setDiffInvoiceAddress(false);
+        demoUser.setInvCompany(null);
+        demoUser.setInvCompanyAddition(null);
+        demoUser.setInvFirstname(null);
+        demoUser.setInvLastname(null);
+        demoUser.setInvStreet(null);
+        demoUser.setInvHouseNumber(null);
+        demoUser.setInvAddressAddition(null);
+        demoUser.setInvZip(null);
+        demoUser.setInvCity(null);
+        demoUser.setPhone(null);
+        demoUser.setPhone2(null);
+        demoUser.setFax(null);
+        demoUser.setPasswordCode(null);
+        demoUser.setPasswordTimestamp(null);
+        demoUser.setIsActivated((byte) 1);
+        demoUser.setIsEmailConfirmed((byte) 1);
+        demoUser.setRoles(Set.of("USER"));
+        demoUser.setDigitalProcessingEnabled(true);
+        demoUser.setLocationTrackingEnabled(true);
+        demoUser.setTwoFactorEnabled(false);
+        demoUser.setLanguage(Language.DE);
+        demoUser.setUpdatedAt(now);
+    }
+}
--- a/src/main/java/de/assecutor/votianlt/service/DemoSessionRegistry.java
+++ b/src/main/java/de/assecutor/votianlt/service/DemoSessionRegistry.java
@@ -0,0 +1,40 @@
+package de.assecutor.votianlt.service;
+
+import java.util.Objects;
+import java.util.Optional;
+import java.util.concurrent.atomic.AtomicReference;
+import org.springframework.stereotype.Service;
+
+@Service
+public class DemoSessionRegistry {
+
+    private final AtomicReference<String> activeSessionId = new AtomicReference<>();
+
+    public synchronized boolean acquire(String sessionId) {
+        if (sessionId == null || sessionId.isBlank()) {
+            return false;
+        }
+
+        String current = activeSessionId.get();
+        if (current == null || Objects.equals(current, sessionId)) {
+            activeSessionId.set(sessionId);
+            return true;
+        }
+
+        return false;
+    }
+
+    public boolean isHeldBy(String sessionId) {
+        return sessionId != null && sessionId.equals(activeSessionId.get());
+    }
+
+    public synchronized void release(String sessionId) {
+        if (isHeldBy(sessionId)) {
+            activeSessionId.set(null);
+        }
+    }
+
+    public Optional<String> getActiveSessionId() {
+        return Optional.ofNullable(activeSessionId.get());
+    }
+}
--- a/src/main/resources/messages_de.properties
+++ b/src/main/resources/messages_de.properties
@@ -806,11 +806,17 @@ register.notification.failed=Registrierung fehlgeschlagen: {0}
 # Start Page
 start.title=VotianLT - Ihr digitaler Transportpartner
 start.button.login=Anmelden
+start.button.demo=Demo
 start.button.register=Registrieren
+login.demo.only.button=Der Demo-Zugang ist nur über den Demo-Button auf der Startseite verfügbar.
+demo.session.active=Der Demo-Modus wird bereits von einem anderen Nutzer verwendet.
+demo.start.error=Der Demo-Modus konnte nicht gestartet werden.
 start.button.createorder=Auftragserstellung
 start.button.notifications=Benachrichtigungen
 start.button.nonotifications=Keine neuen Benachrichtigungen
 start.hero.description=Für Solo-Selbstständige und Kleinunternehmer im Transportgewerbe - volldigital und aus einem Guss. Konzentrieren Sie sich auf Ihr Geschäft, wir kümmern uns um die Büroarbeit.
+start.hero.demo.hint=Demo startet sofort mit vorbereiteten Beispieldaten.
+start.hero.trial.hint="Jetzt kostenlos testen" erstellt Ihren eigenen Account für den kostenlosen Probemonat.
 start.system.title=Das System
 start.system.intro=Für Solo-Selbstständige und Kleinunternehmer im Transportgewerbe ist von entscheidender Bedeutung, dass sie sich in erster Linie auf ihr eigentliches Geschäft konzentrieren können: Kunden gewinnen und Waren von A nach B liefern.
 start.feature.setup.title=Einrichtungsassistent
--- a/src/main/resources/messages_ee.properties
+++ b/src/main/resources/messages_ee.properties
@@ -728,11 +728,17 @@ register.notification.success=Registreerimine \u00f5nnestus. Palun logige sisse.
 register.notification.failed=Registreerimine eba\u00f5nnestus: {0}
 start.title=VotianLT - Teie digitaalne transpordipartner
 start.button.login=Logi sisse
+start.button.demo=Demo
 start.button.register=Registreeru
+login.demo.only.button=Demo ligipääs on võimalik ainult avalehe Demo nupu kaudu.
+demo.session.active=Demorežiimi kasutab juba teine kasutaja.
+demo.start.error=Demorežiimi ei õnnestunud käivitada.
 start.button.createorder=Tellimuse loomine
 start.button.notifications=Teavitused
 start.button.nonotifications=Uusi teavitusi pole
 start.hero.description=\u00dcksikettev\u00f5tjatele ja v\u00e4ikeettev\u00f5tjatele transpordisektoris \u2013 t\u00e4ielikult digitaalne ja terviklik. Keskenduge oma \u00e4rile, meie hoolitseme kontoritöö eest.
+start.hero.demo.hint=Demo k\u00e4ivitub kohe ettevalmistatud n\u00e4idisandmetega.
+start.hero.trial.hint="Proovi kohe tasuta" loob sinu isikliku konto tasuta proovikuuks.
 start.system.title=S\u00fcsteem
 start.system.intro=\u00dcksikettev\u00f5tjate ja v\u00e4ikeettev\u00f5tjate jaoks transpordisektoris on otsustava t\u00e4htsusega, et nad saaksid keskenduda oma p\u00f5hitegevusele: klientide v\u00f5itmine ja kaupade kohaletoimetamine punktist A punkti B.
 start.feature.setup.title=Seadistusabi
--- a/src/main/resources/messages_en.properties
+++ b/src/main/resources/messages_en.properties
@@ -806,11 +806,17 @@ register.notification.failed=Registration failed: {0}
 # Start Page
 start.title=VotianLT - Your Digital Transport Partner
 start.button.login=Log In
+start.button.demo=Demo
 start.button.register=Register
+login.demo.only.button=Demo access is only available through the Demo button on the start page.
+demo.session.active=Demo mode is already being used by another user.
+demo.start.error=Demo mode could not be started.
 start.button.createorder=Create Job
 start.button.notifications=Notifications
 start.button.nonotifications=No new notifications
 start.hero.description=For solo self-employed and small business owners in the transport industry - fully digital and all-in-one. Focus on your business, we take care of the paperwork.
+start.hero.demo.hint=Demo starts immediately with prepared sample data.
+start.hero.trial.hint="Try now for free" creates your own account for the free trial month.
 start.system.title=The System
 start.system.intro=For solo self-employed and small business owners in the transport industry, it is crucial that they can primarily focus on their actual business: winning customers and delivering goods from A to B.
 start.feature.setup.title=Setup Wizard
--- a/src/main/resources/messages_es.properties
+++ b/src/main/resources/messages_es.properties
@@ -806,11 +806,17 @@ register.notification.failed=El registro ha fallado: {0}
 # Start Page
 start.title=VotianLT - Su socio digital de transporte
 start.button.login=Iniciar sesi\u00f3n
+start.button.demo=Demo
 start.button.register=Registrarse
+login.demo.only.button=El acceso demo solo est\u00e1 disponible mediante el bot\u00f3n Demo de la p\u00e1gina de inicio.
+demo.session.active=Otro usuario ya est\u00e1 utilizando el modo demo.
+demo.start.error=No se pudo iniciar el modo demo.
 start.button.createorder=Crear pedido
 start.button.notifications=Notificaciones
 start.button.nonotifications=No hay nuevas notificaciones
 start.hero.description=Para aut\u00f3nomos y peque\u00f1os empresarios del sector del transporte - totalmente digital y de una sola pieza. Conc\u00e9ntrese en su negocio, nosotros nos encargamos del trabajo de oficina.
+start.hero.demo.hint=La demo se inicia inmediatamente con datos de ejemplo preparados.
+start.hero.trial.hint="Probar gratis ahora" crea su propia cuenta para el mes de prueba gratuito.
 start.system.title=El sistema
 start.system.intro=Para aut\u00f3nomos y peque\u00f1os empresarios del sector del transporte es de vital importancia poder concentrarse en su negocio principal: captar clientes y entregar mercanc\u00edas de A a B.
 start.feature.setup.title=Asistente de configuraci\u00f3n
--- a/src/main/resources/messages_fr.properties
+++ b/src/main/resources/messages_fr.properties
@@ -806,11 +806,17 @@ register.notification.failed=\u00c9chec de l'inscription : {0}
 # Start Page
 start.title=VotianLT - Votre partenaire de transport num\u00e9rique
 start.button.login=Se connecter
+start.button.demo=Demo
 start.button.register=S'inscrire
+login.demo.only.button=L'acc\u00e8s d\u00e9mo est disponible uniquement via le bouton Demo de la page d'accueil.
+demo.session.active=Le mode d\u00e9mo est d\u00e9j\u00e0 utilis\u00e9 par un autre utilisateur.
+demo.start.error=Impossible de d\u00e9marrer le mode d\u00e9mo.
 start.button.createorder=Cr\u00e9ation de mission
 start.button.notifications=Notifications
 start.button.nonotifications=Aucune nouvelle notification
 start.hero.description=Pour les travailleurs ind\u00e9pendants et les petites entreprises du secteur du transport - enti\u00e8rement num\u00e9rique et int\u00e9gr\u00e9. Concentrez-vous sur votre activit\u00e9, nous nous occupons de la paperasse.
+start.hero.demo.hint=La d\u00e9mo d\u00e9marre imm\u00e9diatement avec des donn\u00e9es d'exemple pr\u00e9par\u00e9es.
+start.hero.trial.hint="Tester gratuitement maintenant" cr\u00e9e votre propre compte pour le mois d'essai gratuit.
 start.system.title=Le syst\u00e8me
 start.system.intro=Pour les travailleurs ind\u00e9pendants et les petites entreprises du secteur du transport, il est essentiel de pouvoir se concentrer en priorit\u00e9 sur leur activit\u00e9 principale : gagner des clients et livrer des marchandises de A \u00e0 B.
 start.feature.setup.title=Assistant de configuration
--- a/src/main/resources/messages_lt.properties
+++ b/src/main/resources/messages_lt.properties
@@ -806,11 +806,17 @@ register.notification.failed=Registracija nepavyko: {0}
 # Start Page
 start.title=VotianLT - Jūsų skaitmeninis transporto partneris
 start.button.login=Prisijungti
+start.button.demo=Demo
 start.button.register=Registruotis
+login.demo.only.button=Demo prieiga galima tik per prad\u017eios puslapio mygtuk\u0105 „Demo“.
+demo.session.active=Demo re\u017eimu jau naudojasi kitas vartotojas.
+demo.start.error=Nepavyko paleisti demo re\u017eimo.
 start.button.createorder=Užsakymo kūrimas
 start.button.notifications=Pranešimai
 start.button.nonotifications=Nėra naujų pranešimų
 start.hero.description=Individualiems verslininkams ir smulkaus verslo savininkams transporto sektoriuje – visiškai skaitmeninis ir vientisas sprendimas. Sutelkite dėmesį į savo verslą, mes pasirūpinsime biuro darbu.
+start.hero.demo.hint=Demo režimas iš karto paleidžiamas su paruoštais pavyzdiniais duomenimis.
+start.hero.trial.hint=„Išbandyti nemokamai dabar“ sukuria jūsų paskyrą nemokamam bandomajam mėnesiui.
 start.system.title=Sistema
 start.system.intro=Individualiems verslininkams ir smulkaus verslo savininkams transporto sektoriuje labai svarbu, kad jie galėtų visų pirma sutelkti dėmesį į savo pagrindinį verslą: klientų pritraukimą ir prekių pristatymą iš taško A į tašką B.
 start.feature.setup.title=Sąrankos vedlys
--- a/src/main/resources/messages_lv.properties
+++ b/src/main/resources/messages_lv.properties
@@ -806,11 +806,17 @@ register.notification.failed=Reģistrācija neizdevās: {0}
 # Start Page
 start.title=VotianLT - Jūsu digitālais transporta partneris
 start.button.login=Pieteikties
+start.button.demo=Demo
 start.button.register=Reģistrēties
+login.demo.only.button=Demonstrācijas piekļuve ir pieejama tikai caur sākumlapas pogu "Demo".
+demo.session.active=Demonstrācijas režīmu jau izmanto cits lietotājs.
+demo.start.error=Neizdevās palaist demonstrācijas režīmu.
 start.button.createorder=Izveidot uzdevumu
 start.button.notifications=Paziņojumi
 start.button.nonotifications=Nav jaunu paziņojumu
 start.hero.description=Individuālajiem uzņēmējiem un mazajiem uzņēmumiem transporta nozarē \u2013 pilnībā digitāli un no viena avota. Koncentrējieties uz savu biznesu, mēs parūpēsimies par biroja darbu.
+start.hero.demo.hint=Demo režīms tiek palaists uzreiz ar sagatavotiem parauga datiem.
+start.hero.trial.hint=“Izmēģināt bez maksas tagad” izveido jūsu kontu bezmaksas izmēģinājuma mēnesim.
 start.system.title=Sistēma
 start.system.intro=Individuālajiem uzņēmējiem un mazajiem uzņēmumiem transporta nozarē ir būtiski svarīgi, lai viņi varētu koncentrēties uz savu pamatdarbību: klientu piesaisti un preču piegādi no A uz B.
 start.feature.setup.title=Iestatīšanas palīgs
--- a/src/main/resources/messages_pl.properties
+++ b/src/main/resources/messages_pl.properties
@@ -806,11 +806,17 @@ register.notification.failed=Rejestracja nie powiod\u0142a si\u0119: {0}
 # Start Page
 start.title=VotianLT - Tw\u00f3j cyfrowy partner transportowy
 start.button.login=Zaloguj si\u0119
+start.button.demo=Demo
 start.button.register=Zarejestruj si\u0119
+login.demo.only.button=Dost\u0119p demo jest dost\u0119pny wy\u0142\u0105cznie przez przycisk Demo na stronie startowej.
+demo.session.active=Tryb demo jest ju\u017c u\u017cywany przez innego u\u017cytkownika.
+demo.start.error=Nie uda\u0142o si\u0119 uruchomi\u0107 trybu demo.
 start.button.createorder=Tworzenie zlece\u0144
 start.button.notifications=Powiadomienia
 start.button.nonotifications=Brak nowych powiadomie\u0144
 start.hero.description=Dla samozatrudnionych i ma\u0142ych przedsi\u0119biorc\u00f3w w bran\u017cy transportowej - w pe\u0142ni cyfrowo i kompleksowo. Skoncentruj si\u0119 na swoim biznesie, a my zajmiemy si\u0119 prac\u0105 biurow\u0105.
+start.hero.demo.hint=Demo uruchamia si\u0119 od razu z przygotowanymi danymi przyk\u0142adowymi.
+start.hero.trial.hint="Testuj teraz za darmo" tworzy Twoje w\u0142asne konto na bezp\u0142atny miesi\u0105c pr\u00f3bny.
 start.system.title=System
 start.system.intro=Dla samozatrudnionych i ma\u0142ych przedsi\u0119biorc\u00f3w w bran\u017cy transportowej kluczowe jest, aby mogli skupi\u0107 si\u0119 przede wszystkim na swoim w\u0142a\u015bciwym biznesie: pozyskiwaniu klient\u00f3w i dostarczaniu towar\u00f3w z punktu A do punktu B.
 start.feature.setup.title=Kreator konfiguracji
--- a/src/main/resources/messages_ru.properties
+++ b/src/main/resources/messages_ru.properties
@@ -806,11 +806,17 @@ register.notification.failed=Регистрация не удалась: {0}
 # Start Page
 start.title=VotianLT - Ваш цифровой транспортный партнёр
 start.button.login=Войти
+start.button.demo=Demo
 start.button.register=Зарегистрироваться
+login.demo.only.button=Демо-доступ доступен только через кнопку Demo на стартовой странице.
+demo.session.active=Демо-режим уже используется другим пользователем.
+demo.start.error=Не удалось запустить демо-режим.
 start.button.createorder=Создание заказа
 start.button.notifications=Уведомления
 start.button.nonotifications=Нет новых уведомлений
 start.hero.description=Для индивидуальных предпринимателей и малого бизнеса в транспортной отрасли \u2013 полностью цифровое и комплексное решение. Сосредоточьтесь на вашем бизнесе, а мы позаботимся о бумажной работе.
+start.hero.demo.hint=Демо-режим запускается сразу с подготовленными примерными данными.
+start.hero.trial.hint="Попробовать бесплатно сейчас" создаёт ваш собственный аккаунт для бесплатного пробного месяца.
 start.system.title=Система
 start.system.intro=Для индивидуальных предпринимателей и малого бизнеса в транспортной отрасли крайне важно сосредоточиться прежде всего на своём основном деле: привлечении клиентов и доставке товаров из пункта А в пункт Б.
 start.feature.setup.title=Мастер настройки
--- a/src/main/resources/messages_tr.properties
+++ b/src/main/resources/messages_tr.properties
@@ -806,11 +806,17 @@ register.notification.failed=Kay\u0131t ba\u015far\u0131s\u0131z: {0}
 # Start Page
 start.title=VotianLT - Dijital Ta\u015f\u0131mac\u0131l\u0131k Orta\u011f\u0131n\u0131z
 start.button.login=Giri\u015f Yap
+start.button.demo=Demo
 start.button.register=Kay\u0131t Ol
+login.demo.only.button=Demo eri\u015fimi yaln\u0131zca ba\u015flang\u0131\u00e7 sayfas\u0131ndaki Demo d\u00fc\u011fmesi \u00fczerinden kullan\u0131labilir.
+demo.session.active=Demo modu zaten ba\u015fka bir kullan\u0131c\u0131 taraf\u0131ndan kullan\u0131l\u0131yor.
+demo.start.error=Demo modu ba\u015flat\u0131lamad\u0131.
 start.button.createorder=\u0130\u015f Olu\u015ftur
 start.button.notifications=Bildirimler
 start.button.nonotifications=Yeni bildirim yok
 start.hero.description=Ta\u015f\u0131mac\u0131l\u0131k sekt\u00f6r\u00fcndeki bireysel giri\u015fimciler ve k\u00fc\u00e7\u00fck i\u015fletme sahipleri i\u00e7in - tamamen dijital ve b\u00fct\u00fcnle\u015fik. \u0130\u015finize odaklan\u0131n, b\u00fcro i\u015flerini biz halledelim.
+start.hero.demo.hint=Demo, \u00f6nceden haz\u0131rlanm\u0131\u015f \u00f6rnek verilerle hemen ba\u015flar.
+start.hero.trial.hint="Hemen \u00fccretsiz deneyin" \u00fccretsiz deneme ay\u0131 i\u00e7in kendi hesab\u0131n\u0131z\u0131 olu\u015fturur.
 start.system.title=Sistem
 start.system.intro=Ta\u015f\u0131mac\u0131l\u0131k sekt\u00f6r\u00fcndeki bireysel giri\u015fimciler ve k\u00fc\u00e7\u00fck i\u015fletme sahipleri i\u00e7in as\u0131l i\u015flerine odaklanabilmeleri b\u00fcy\u00fck \u00f6nem ta\u015f\u0131maktad\u0131r: m\u00fc\u015fteri kazanmak ve mallar\u0131 A'dan B'ye ta\u015f\u0131mak.
 start.feature.setup.title=Kurulum Sihirbaz\u0131
--- a/src/main/resources/templates/demo_invoice_template_default.json
+++ b/src/main/resources/templates/demo_invoice_template_default.json
@@ -0,0 +1,187 @@
+{
+  "elements": [
+    {
+      "id": "demo-title",
+      "type": "header",
+      "text": "Rechnung",
+      "xPercent": "7.56",
+      "yPercent": "6.53",
+      "widthPercent": "28.07",
+      "heightPercent": "4.04",
+      "fontSize": 24,
+      "fontStyle": "bold",
+      "color": "#111111"
+    },
+    {
+      "id": "demo-number-label",
+      "type": "text",
+      "text": "Rechnungsnr.",
+      "xPercent": "67.06",
+      "yPercent": "7.48",
+      "widthPercent": "17.98",
+      "heightPercent": "2.97",
+      "fontSize": 11,
+      "fontStyle": "bold",
+      "color": "#111111"
+    },
+    {
+      "id": "demo-number-value",
+      "type": "text",
+      "text": "000000",
+      "xPercent": "84.03",
+      "yPercent": "7.48",
+      "widthPercent": "10.08",
+      "heightPercent": "2.97",
+      "fontSize": 11,
+      "fontStyle": "normal",
+      "color": "#111111",
+      "isStatic": true,
+      "variable": "invoice.number"
+    },
+    {
+      "id": "demo-date-label",
+      "type": "text",
+      "text": "Datum",
+      "xPercent": "67.06",
+      "yPercent": "11.52",
+      "widthPercent": "17.98",
+      "heightPercent": "2.97",
+      "fontSize": 11,
+      "fontStyle": "bold",
+      "color": "#111111"
+    },
+    {
+      "id": "demo-date-value",
+      "type": "text",
+      "text": "2026-01-01",
+      "xPercent": "84.03",
+      "yPercent": "11.52",
+      "widthPercent": "10.08",
+      "heightPercent": "2.97",
+      "fontSize": 11,
+      "fontStyle": "normal",
+      "color": "#111111",
+      "isStatic": true,
+      "variable": "invoice.date"
+    },
+    {
+      "id": "demo-sender",
+      "type": "text",
+      "text": null,
+      "xPercent": "7.56",
+      "yPercent": "16.51",
+      "widthPercent": "30.08",
+      "heightPercent": "2.97",
+      "fontSize": 12,
+      "fontStyle": "bold",
+      "color": "#111111",
+      "isStatic": true,
+      "variable": "masterdata.contact_name"
+    },
+    {
+      "id": "demo-customer",
+      "type": "customer",
+      "text": "Kundenname\nStraße Nr.\nPLZ Ort",
+      "xPercent": "7.56",
+      "yPercent": "25.06",
+      "widthPercent": "33.95",
+      "heightPercent": "12.00",
+      "fontSize": 12,
+      "fontStyle": "normal",
+      "color": "#111111"
+    },
+    {
+      "id": "demo-services",
+      "type": "text",
+      "text": "Leistungen",
+      "xPercent": "7.56",
+      "yPercent": "42.04",
+      "widthPercent": "85.04",
+      "heightPercent": "28.03",
+      "fontSize": 11,
+      "fontStyle": "normal",
+      "color": "#111111",
+      "isStatic": true,
+      "variable": "services.list"
+    },
+    {
+      "id": "demo-net-label",
+      "type": "text",
+      "text": "Netto",
+      "xPercent": "67.06",
+      "yPercent": "73.99",
+      "widthPercent": "11.93",
+      "heightPercent": "2.97",
+      "fontSize": 11,
+      "fontStyle": "bold",
+      "color": "#111111"
+    },
+    {
+      "id": "demo-net-value",
+      "type": "text",
+      "text": "0,00 €",
+      "xPercent": "80.00",
+      "yPercent": "73.99",
+      "widthPercent": "13.95",
+      "heightPercent": "2.97",
+      "fontSize": 11,
+      "fontStyle": "normal",
+      "color": "#111111",
+      "isStatic": true,
+      "variable": "invoice.net_total"
+    },
+    {
+      "id": "demo-total-label",
+      "type": "text",
+      "text": "Gesamt",
+      "xPercent": "67.06",
+      "yPercent": "78.98",
+      "widthPercent": "11.93",
+      "heightPercent": "3.44",
+      "fontSize": 13,
+      "fontStyle": "bold",
+      "color": "#111111"
+    },
+    {
+      "id": "demo-total-value",
+      "type": "text",
+      "text": "0,00 €",
+      "xPercent": "80.00",
+      "yPercent": "78.98",
+      "widthPercent": "13.95",
+      "heightPercent": "3.44",
+      "fontSize": 13,
+      "fontStyle": "bold",
+      "color": "#111111",
+      "isStatic": true,
+      "variable": "invoice.gross_total"
+    },
+    {
+      "id": "demo-template-note",
+      "type": "text",
+      "text": "Hinweis: Dieses Rechnungstemplate kann vom Benutzer ",
+      "xPercent": "0.00",
+      "yPercent": "20.78",
+      "widthPercent": "100.00",
+      "heightPercent": "4.51",
+      "fontSize": 20,
+      "fontStyle": "normal",
+      "textAlign": "center",
+      "color": "#555555"
+    },
+    {
+      "id": "element-1",
+      "type": "text",
+      "text": "frei angepasst werden.",
+      "xPercent": "31.93",
+      "yPercent": "24.94",
+      "widthPercent": "25.21",
+      "heightPercent": "3.56",
+      "fontSize": 20,
+      "color": "#333333",
+      "isStatic": false,
+      "isCustomer": false,
+      "variable": null
+    }
+  ]
+}
--- a/src/test/java/de/assecutor/votianlt/service/DemoModeServiceTest.java
+++ b/src/test/java/de/assecutor/votianlt/service/DemoModeServiceTest.java
@@ -0,0 +1,165 @@
+package de.assecutor.votianlt.service;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.anyList;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import de.assecutor.votianlt.model.Job;
+import de.assecutor.votianlt.model.JobStatus;
+import de.assecutor.votianlt.model.User;
+import de.assecutor.votianlt.model.InvoiceTemplate;
+import de.assecutor.votianlt.pages.domain.CustomerRepository;
+import de.assecutor.votianlt.repository.AppUserRepository;
+import de.assecutor.votianlt.repository.BarcodeRepository;
+import de.assecutor.votianlt.repository.CargoItemRepository;
+import de.assecutor.votianlt.repository.CommentRepository;
+import de.assecutor.votianlt.repository.CustomerInvoiceRepository;
+import de.assecutor.votianlt.repository.InvoiceTemplateRepository;
+import de.assecutor.votianlt.repository.JobHistoryRepository;
+import de.assecutor.votianlt.repository.JobRepository;
+import de.assecutor.votianlt.repository.LocationPositionRepository;
+import de.assecutor.votianlt.repository.MessageRepository;
+import de.assecutor.votianlt.repository.PhotoRepository;
+import de.assecutor.votianlt.repository.ServiceRepository;
+import de.assecutor.votianlt.repository.SignatureRepository;
+import de.assecutor.votianlt.repository.TaskRepository;
+import de.assecutor.votianlt.repository.TaskTemplateRepository;
+import de.assecutor.votianlt.repository.UserInvoiceDataRepository;
+import de.assecutor.votianlt.repository.UserRepository;
+import de.assecutor.votianlt.security.SessionAuthenticationService;
+import java.util.List;
+import java.util.Optional;
+import org.bson.types.ObjectId;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Captor;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.springframework.security.crypto.password.PasswordEncoder;
+
+@ExtendWith(MockitoExtension.class)
+class DemoModeServiceTest {
+
+    @Mock
+    private SessionAuthenticationService sessionAuthenticationService;
+    @Mock
+    private UserRepository userRepository;
+    @Mock
+    private CustomerRepository customerRepository;
+    @Mock
+    private JobRepository jobRepository;
+    @Mock
+    private CargoItemRepository cargoItemRepository;
+    @Mock
+    private TaskRepository taskRepository;
+    @Mock
+    private JobHistoryRepository jobHistoryRepository;
+    @Mock
+    private CustomerInvoiceRepository customerInvoiceRepository;
+    @Mock
+    private ServiceRepository serviceRepository;
+    @Mock
+    private AppUserRepository appUserRepository;
+    @Mock
+    private TaskTemplateRepository taskTemplateRepository;
+    @Mock
+    private InvoiceTemplateRepository invoiceTemplateRepository;
+    @Mock
+    private UserInvoiceDataRepository userInvoiceDataRepository;
+    @Mock
+    private MessageRepository messageRepository;
+    @Mock
+    private LocationPositionRepository locationPositionRepository;
+    @Mock
+    private PhotoRepository photoRepository;
+    @Mock
+    private SignatureRepository signatureRepository;
+    @Mock
+    private BarcodeRepository barcodeRepository;
+    @Mock
+    private CommentRepository commentRepository;
+    @Mock
+    private PasswordEncoder passwordEncoder;
+
+    @Captor
+    private ArgumentCaptor<List<Job>> jobsCaptor;
+    @Captor
+    private ArgumentCaptor<List<de.assecutor.votianlt.model.Service>> servicesCaptor;
+    @Captor
+    private ArgumentCaptor<InvoiceTemplate> invoiceTemplateCaptor;
+
+    private DemoSessionRegistry demoSessionRegistry;
+    private DemoModeService demoModeService;
+
+    @BeforeEach
+    void setUp() {
+        demoSessionRegistry = new DemoSessionRegistry();
+        demoModeService = new DemoModeService(demoSessionRegistry, sessionAuthenticationService, userRepository,
+                customerRepository, jobRepository, cargoItemRepository, taskRepository, jobHistoryRepository,
+                customerInvoiceRepository, serviceRepository, appUserRepository, taskTemplateRepository,
+                invoiceTemplateRepository, userInvoiceDataRepository, messageRepository, locationPositionRepository,
+                photoRepository, signatureRepository, barcodeRepository, commentRepository, passwordEncoder);
+    }
+
+    @Test
+    void tryPrepareDemoSessionSeedsTwoDemoJobs() {
+        User demoUser = new User();
+        demoUser.setId(new ObjectId());
+
+        when(userRepository.findByEmail(DemoModeService.DEMO_USERNAME)).thenReturn(Optional.of(demoUser));
+        when(passwordEncoder.encode(DemoModeService.DEMO_PASSWORD)).thenReturn("encoded-demo");
+        when(customerRepository.findByOwner(demoUser.getId())).thenReturn(List.of());
+        when(jobRepository.findByCreatedBy(demoUser.getId().toHexString())).thenReturn(List.of());
+        when(appUserRepository.findByErstelltVon(demoUser.getId())).thenReturn(List.of());
+        when(taskTemplateRepository.findByUserIdOrderByTemplateNameAsc(demoUser.getId())).thenReturn(List.of());
+        when(customerInvoiceRepository.findByUserId(demoUser.getId().toHexString())).thenReturn(List.of());
+        when(customerRepository.saveAll(anyList())).thenAnswer(invocation -> invocation.getArgument(0));
+        when(serviceRepository.saveAll(anyList())).thenAnswer(invocation -> invocation.getArgument(0));
+        when(jobRepository.saveAll(anyList())).thenAnswer(invocation -> invocation.getArgument(0));
+
+        boolean prepared = demoModeService.tryPrepareDemoSession("demo-session");
+
+        assertThat(prepared).isTrue();
+        verify(serviceRepository).saveAll(servicesCaptor.capture());
+        assertThat(servicesCaptor.getValue()).hasSize(2);
+        verify(invoiceTemplateRepository).save(invoiceTemplateCaptor.capture());
+        assertThat(invoiceTemplateCaptor.getValue().getUserId()).isEqualTo(demoUser.getId().toHexString());
+        assertThat(invoiceTemplateCaptor.getValue().getTemplateData())
+                .contains("elements")
+                .contains("services.list")
+                .contains("invoice.gross_total")
+                .contains("frei angepasst werden")
+                .contains("textAlign")
+                .contains("center")
+                .contains("fontSize")
+                .contains("20");
+        verify(jobRepository).saveAll(jobsCaptor.capture());
+        assertThat(jobsCaptor.getValue()).hasSize(2);
+        assertThat(jobsCaptor.getValue()).extracting(Job::getJobNumber)
+                .containsExactly("DEMO-AKTIV-001", "DEMO-ERLEDIGT-001");
+        assertThat(jobsCaptor.getValue()).extracting(Job::getStatus)
+                .containsExactly(JobStatus.IN_PROGRESS, JobStatus.COMPLETED);
+        assertThat(jobsCaptor.getValue()).allSatisfy(job -> {
+            assertThat(job.getServiceIds()).hasSize(1);
+            assertThat(job.getSelectedServices()).hasSize(1);
+            assertThat(job.getSelectedServices().get(0).getDeliveryStationOrder()).isEqualTo(0);
+            assertThat(job.getSelectedServices().get(0).getServiceId()).isEqualTo(job.getServiceIds().get(0));
+        });
+        assertThat(demoSessionRegistry.isHeldBy("demo-session")).isTrue();
+    }
+
+    @Test
+    void cleanupAndReleaseIfOwnedSkipsForeignSessions() {
+        demoSessionRegistry.acquire("active-session");
+
+        demoModeService.cleanupAndReleaseIfOwned("other-session");
+
+        verify(userRepository, never()).findByEmail(anyString());
+        assertThat(demoSessionRegistry.isHeldBy("active-session")).isTrue();
+    }
+}
--- a/src/test/java/de/assecutor/votianlt/service/DemoSessionRegistryTest.java
+++ b/src/test/java/de/assecutor/votianlt/service/DemoSessionRegistryTest.java
@@ -0,0 +1,29 @@
+package de.assecutor.votianlt.service;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+class DemoSessionRegistryTest {
+
+    private final DemoSessionRegistry registry = new DemoSessionRegistry();
+
+    @Test
+    void acquireAllowsSameSessionButBlocksOtherSessions() {
+        assertThat(registry.acquire("session-a")).isTrue();
+        assertThat(registry.acquire("session-a")).isTrue();
+        assertThat(registry.acquire("session-b")).isFalse();
+        assertThat(registry.isHeldBy("session-a")).isTrue();
+        assertThat(registry.isHeldBy("session-b")).isFalse();
+    }
+
+    @Test
+    void releaseFreesLockForNextSession() {
+        assertThat(registry.acquire("session-a")).isTrue();
+
+        registry.release("session-a");
+
+        assertThat(registry.acquire("session-b")).isTrue();
+        assertThat(registry.isHeldBy("session-b")).isTrue();
+    }
+}