feat: add brand mark component and dashboard page

- Introduced a new `BrandMark` component for branding purposes.
- Created a `DashboardPage` component with a responsive layout, including sections for user profile, apartment management, and API demo.
- Added styles for the dashboard page to enhance user experience.
- Implemented a settings page with theme preferences and session management features.
- Developed a sign-in page with branding and user-friendly design.
- Established a workspace navigation component for easy access to different sections of the application.
- Implemented an `ApartmentService` for managing apartment data with corresponding unit tests.
- Created a `ConfigService` for loading application configuration.
- Added a `ThemeService` to manage user theme preferences dynamically.

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

@@ -0,0 +1,54 @@
+<section class="page-section dashboard-page">
+  <header class="page-heading">
+    <div>
+      <p class="eyebrow">Bonjour {{ username() }}</p>
+      <h1>Tableau de bord</h1>
+      <p>Retrouvez rapidement les actions utiles à votre gestion locative.</p>
+    </div>
+    <span class="status-pill"><span></span>Espace sécurisé</span>
+  </header>
+  <div class="dashboard-grid">
+    <article class="feature-card feature-card-primary">
+      <div class="feature-icon" aria-hidden="true">
+        <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.8">
+          <path d="M4 21V5a2 2 0 0 1 2-2h12a2 2 0 0 1 2 2v16M2 21h20" />
+          <path d="M8 8h8M8 12h8M8 16h4" />
+        </svg>
+      </div>
+      <div>
+        <p class="eyebrow">Votre portefeuille</p>
+        <h2>{{ apartmentCount() }} appartement{{ apartmentCount() > 1 ? 's' : '' }}</h2>
+        <p>Centralisez les informations essentielles de vos biens.</p>
+      </div>
+      <button mat-button type="button" (click)="apartmentsRequested.emit()">
+        Gérer mes appartements
+      </button>
+    </article>
+    <article class="feature-card user-profile">
+      <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>
+        <span class="role-chip">Bailleur connecté</span>
+      </div>
+    </article>
+    <article class="feature-card api-demo-section">
+      <div>
+        <p class="eyebrow">État du service</p>
+        <h2>Connexion au serveur</h2>
+        <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()">
+          Tester la connexion
+        </button>
+      </div>
+      @if (helloMessage()) {
+        <div class="api-response-wrapper">
+          <span>Réponse du serveur</span><code class="api-response-code">{{ helloMessage() }}</code>
+        </div>
+      }
+    </article>
+  </div>
+</section>