feat: integrate toast notifications in settings and layout components

- Added ToastService for managing toast notifications.
- Replaced alert in settings component with toast notifications for success and error messages.
- Included ToastComponent in layout for displaying notifications.
- Created loading spinner component for better user experience.
- Implemented domain detail component with detailed views for certificates, requirements, and services.
- Added functionality to manage and display SSL certificates and their statuses.
- Introduced a registry manager class for handling Docker registry operations.

ui/src/app/features/settings/settings.component.ts

@@ -2,6 +2,7 @@ import { Component, OnInit, inject, signal } from '@angular/core';
 import { CommonModule } from '@angular/common';
 import { FormsModule } from '@angular/forms';
 import { ApiService } from '../../core/services/api.service';
+import { ToastService } from '../../core/services/toast.service';
 
 @Component({
   selector: 'app-settings',
@@ -67,6 +68,7 @@ import { ApiService } from '../../core/services/api.service';
 })
 export class SettingsComponent implements OnInit {
   private apiService = inject(ApiService);
+  private toastService = inject(ToastService);
   settings: any = {};
 
   ngOnInit(): void {
@@ -90,7 +92,9 @@ export class SettingsComponent implements OnInit {
     );
 
     Promise.all(promises).then(() => {
-      alert('Settings saved successfully');
+      this.toastService.success('Settings saved successfully');
+    }).catch((error) => {
+      this.toastService.error('Failed to save settings: ' + (error.message || 'Unknown error'));
     });
   }
 }