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/apartment-form/apartment-form.spec.ts

@@ -0,0 +1,53 @@
+import { TestBed } from '@angular/core/testing';
+import { vi } from 'vitest';
+import { ApartmentForm } from './apartment-form';
+
+describe('ApartmentForm', () => {
+  it('initializes its fields from the apartment being edited', () => {
+    const fixture = TestBed.createComponent(ApartmentForm);
+    fixture.componentRef.setInput('apartment', {
+      id: 'apt-1',
+      name: 'T2 Paris 15',
+      address: '45 rue des Entrepreneurs, 75015 Paris',
+      purchasePrice: 250000,
+      description: 'Cinquième étage',
+    });
+    fixture.detectChanges();
+
+    const form = fixture.componentInstance;
+    expect(form.name()).toBe('T2 Paris 15');
+    expect(form.purchasePrice()).toBe(250000);
+  });
+
+  it('shows a validation error instead of emitting an incomplete apartment', () => {
+    const fixture = TestBed.createComponent(ApartmentForm);
+    const form = fixture.componentInstance;
+    const saved = vi.fn();
+    form.saved.subscribe(saved);
+
+    form.save();
+
+    expect(form.error()).toContain('Veuillez remplir tous les champs obligatoires');
+    expect(saved).not.toHaveBeenCalled();
+  });
+
+  it('emits a trimmed apartment draft when valid', () => {
+    const fixture = TestBed.createComponent(ApartmentForm);
+    const form = fixture.componentInstance;
+    const saved = vi.fn();
+    form.saved.subscribe(saved);
+    form.name.set(' T2 Paris 15 ');
+    form.address.set(' 45 rue des Entrepreneurs ');
+    form.purchasePrice.set(250000);
+    form.description.set(' Cinquième étage ');
+
+    form.save();
+
+    expect(saved).toHaveBeenCalledWith({
+      name: 'T2 Paris 15',
+      address: '45 rue des Entrepreneurs',
+      purchasePrice: 250000,
+      description: 'Cinquième étage',
+    });
+  });
+});