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/services/session.service.ts

@@ -0,0 +1,25 @@
+import { HttpClient } from '@angular/common/http';
+import { Injectable, inject, signal } from '@angular/core';
+
+@Injectable({ providedIn: 'root' })
+export class SessionService {
+  private readonly http = inject(HttpClient);
+  readonly isLoggedIn = signal(false);
+  readonly username = signal('');
+  readonly email = signal('');
+
+  refresh(): void {
+    this.http.get<{ authenticated: boolean; username?: string; email?: string }>('/api/user').subscribe({
+      next: (user) => {
+        this.isLoggedIn.set(user.authenticated);
+        this.username.set(user.authenticated ? (user.username || 'User') : '');
+        this.email.set(user.authenticated ? (user.email || '') : '');
+      },
+      error: () => {
+        this.isLoggedIn.set(false);
+        this.username.set('');
+        this.email.set('');
+      },
+    });
+  }
+}