feat: Add main application views and structure

- Implemented CreateInstanceView for creating new instances.
- Added HostsView for managing SSH hosts with CRUD operations.
- Created InstancesView for displaying and managing instances.
- Developed LogsView for viewing operation logs.
- Introduced SecretsView for managing secrets associated with hosts.
- Established SettingsView for configuring application settings.
- Created MainWindow as the main application window with navigation.
- Added app manifest and configuration files for logging and settings.

OTSSignsOrchestrator.Desktop/ViewModels/SecretsViewModel.cs

@@ -0,0 +1,68 @@
+using System.Collections.ObjectModel;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+using OTSSignsOrchestrator.Core.Data;
+using OTSSignsOrchestrator.Core.Models.Entities;
+using OTSSignsOrchestrator.Core.Services;
+using OTSSignsOrchestrator.Desktop.Services;
+
+namespace OTSSignsOrchestrator.Desktop.ViewModels;
+
+/// <summary>
+/// ViewModel for viewing and managing Docker Swarm secrets on a remote host.
+/// </summary>
+public partial class SecretsViewModel : ObservableObject
+{
+    private readonly IServiceProvider _services;
+
+    [ObservableProperty] private ObservableCollection<SecretListItem> _secrets = new();
+    [ObservableProperty] private ObservableCollection<SshHost> _availableHosts = new();
+    [ObservableProperty] private SshHost? _selectedSshHost;
+    [ObservableProperty] private string _statusMessage = string.Empty;
+    [ObservableProperty] private bool _isBusy;
+
+    public SecretsViewModel(IServiceProvider services)
+    {
+        _services = services;
+        _ = LoadHostsAsync();
+    }
+
+    private async Task LoadHostsAsync()
+    {
+        using var scope = _services.CreateScope();
+        var db = scope.ServiceProvider.GetRequiredService<XiboContext>();
+        var hosts = await db.SshHosts.OrderBy(h => h.Label).ToListAsync();
+        AvailableHosts = new ObservableCollection<SshHost>(hosts);
+    }
+
+    [RelayCommand]
+    private async Task LoadSecretsAsync()
+    {
+        if (SelectedSshHost == null)
+        {
+            StatusMessage = "Select an SSH host first.";
+            return;
+        }
+
+        IsBusy = true;
+        try
+        {
+            var secretsSvc = _services.GetRequiredService<SshDockerSecretsService>();
+            secretsSvc.SetHost(SelectedSshHost);
+
+            var items = await secretsSvc.ListSecretsAsync();
+            Secrets = new ObservableCollection<SecretListItem>(items);
+            StatusMessage = $"Found {items.Count} secret(s) on {SelectedSshHost.Label}.";
+        }
+        catch (Exception ex)
+        {
+            StatusMessage = $"Error: {ex.Message}";
+        }
+        finally
+        {
+            IsBusy = false;
+        }
+    }
+}