Refactor application structure to use WorkspaceService for state management

- Removed direct state management from components and centralized it in WorkspaceService.
- Updated ApartmentsPage, TenantsPage, LeasesPage, and DashboardPage to utilize WorkspaceService for data handling.
- Introduced SessionService to manage user session state and authentication.
- Simplified component templates to reflect new service-based architecture.
- Removed unused ConfigService and its tests.
- Added lease.html template for lease document generation.
- Created app.routes.spec.ts for route mapping tests.

frontend/src/app/components/dashboard-page/dashboard-page.html

@@ -1,7 +1,7 @@
 <section class="page-section dashboard-page">
   <header class="page-heading">
     <div>
-      <p class="eyebrow">Bonjour {{ username() }}</p>
+      <p class="eyebrow">Bonjour {{ session.username() }}</p>
       <h1>Tableau de bord</h1>
       <p>Retrouvez rapidement les actions utiles à votre gestion locative.</p>
     </div>
@@ -17,10 +17,10 @@
       </div>
       <div>
         <p class="eyebrow">Votre portefeuille</p>
-        <h2>{{ apartmentCount() }} appartement{{ apartmentCount() > 1 ? 's' : '' }}</h2>
+        <h2>{{ workspace.apartments().length }} appartement{{ workspace.apartments().length > 1 ? 's' : '' }}</h2>
         <p>Centralisez les informations essentielles de vos biens.</p>
       </div>
-      <button mat-button type="button" (click)="apartmentsRequested.emit()">
+      <button mat-button type="button" (click)="showApartments()">
         Gérer mes appartements
       </button>
     </article>
@@ -28,8 +28,8 @@
       <div class="large-avatar">{{ userInitial() }}</div>
       <div class="user-details">
         <p class="eyebrow">Compte actif</p>
-        <h3>{{ username() }}</h3>
-        <p class="user-email">{{ email() }}</p>
+        <h3>{{ session.username() }}</h3>
+        <p class="user-email">{{ session.email() }}</p>
         <span class="role-chip">Bailleur connecté</span>
       </div>
     </article>
@@ -40,7 +40,7 @@
         <p>Vérifiez que votre espace communique correctement avec le service sécurisé.</p>
       </div>
       <div class="api-actions">
-        <button mat-stroked-button type="button" (click)="connectionCheckRequested.emit()">
+        <button mat-stroked-button type="button" (click)="checkConnection()">
           Tester la connexion
         </button>
       </div>