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.ts

@@ -0,0 +1,50 @@
+import { Component, effect, input, output, signal } from '@angular/core';
+import { FormsModule } from '@angular/forms';
+import { MatButtonModule } from '@angular/material/button';
+import { MatFormFieldModule } from '@angular/material/form-field';
+import { MatInputModule } from '@angular/material/input';
+import { Apartment } from '../../services/apartment.service';
+
+@Component({
+  selector: 'app-apartment-form',
+  imports: [FormsModule, MatButtonModule, MatFormFieldModule, MatInputModule],
+  templateUrl: './apartment-form.html',
+  styleUrl: './apartment-form.css',
+})
+export class ApartmentForm {
+  readonly apartment = input<Apartment | null>(null);
+  readonly closed = output<void>();
+  readonly saved = output<Apartment>();
+
+  readonly name = signal('');
+  readonly address = signal('');
+  readonly purchasePrice = signal(0);
+  readonly description = signal('');
+  readonly error = signal('');
+
+  constructor() {
+    effect(() => this.resetForm(this.apartment()));
+  }
+
+  save(): void {
+    if (!this.name().trim() || !this.address().trim() || this.purchasePrice() <= 0) {
+      this.error.set('Veuillez remplir tous les champs obligatoires (Nom, Adresse, Prix > 0).');
+      return;
+    }
+
+    this.saved.emit({
+      name: this.name().trim(),
+      address: this.address().trim(),
+      purchasePrice: this.purchasePrice(),
+      description: this.description().trim(),
+    });
+  }
+
+  private resetForm(apartment: Apartment | null): void {
+    this.name.set(apartment?.name ?? '');
+    this.address.set(apartment?.address ?? '');
+    this.purchasePrice.set(apartment?.purchasePrice ?? 0);
+    this.description.set(apartment?.description ?? '');
+    this.error.set('');
+  }
+}