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/InstancesViewModel.cs

@@ -0,0 +1,186 @@
+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 listing, viewing, and managing CMS instances.
+/// </summary>
+public partial class InstancesViewModel : ObservableObject
+{
+    private readonly IServiceProvider _services;
+
+    [ObservableProperty] private ObservableCollection<CmsInstance> _instances = new();
+    [ObservableProperty] private CmsInstance? _selectedInstance;
+    [ObservableProperty] private string _statusMessage = string.Empty;
+    [ObservableProperty] private bool _isBusy;
+    [ObservableProperty] private string _filterText = string.Empty;
+    [ObservableProperty] private ObservableCollection<StackInfo> _remoteStacks = new();
+    [ObservableProperty] private ObservableCollection<ServiceInfo> _selectedServices = new();
+
+    // Available SSH hosts for the dropdown
+    [ObservableProperty] private ObservableCollection<SshHost> _availableHosts = new();
+    [ObservableProperty] private SshHost? _selectedSshHost;
+
+    public InstancesViewModel(IServiceProvider services)
+    {
+        _services = services;
+        _ = InitAsync();
+    }
+
+    private async Task InitAsync()
+    {
+        await LoadHostsAsync();
+        await LoadInstancesAsync();
+    }
+
+    [RelayCommand]
+    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 LoadInstancesAsync()
+    {
+        IsBusy = true;
+        try
+        {
+            using var scope = _services.CreateScope();
+            var db = scope.ServiceProvider.GetRequiredService<XiboContext>();
+
+            var query = db.CmsInstances.Include(i => i.SshHost).AsQueryable();
+            if (!string.IsNullOrWhiteSpace(FilterText))
+            {
+                query = query.Where(i =>
+                    i.CustomerName.Contains(FilterText) ||
+                    i.StackName.Contains(FilterText));
+            }
+
+            var items = await query.OrderByDescending(i => i.CreatedAt).ToListAsync();
+            Instances = new ObservableCollection<CmsInstance>(items);
+            StatusMessage = $"Loaded {items.Count} instance(s).";
+        }
+        catch (Exception ex)
+        {
+            StatusMessage = $"Error: {ex.Message}";
+        }
+        finally
+        {
+            IsBusy = false;
+        }
+    }
+
+    [RelayCommand]
+    private async Task RefreshRemoteStacksAsync()
+    {
+        if (SelectedSshHost == null)
+        {
+            StatusMessage = "Select an SSH host first.";
+            return;
+        }
+
+        IsBusy = true;
+        StatusMessage = $"Listing stacks on {SelectedSshHost.Label}...";
+        try
+        {
+            var dockerCli = _services.GetRequiredService<SshDockerCliService>();
+            dockerCli.SetHost(SelectedSshHost);
+
+            var stacks = await dockerCli.ListStacksAsync();
+            RemoteStacks = new ObservableCollection<StackInfo>(stacks);
+            StatusMessage = $"Found {stacks.Count} stack(s) on {SelectedSshHost.Label}.";
+        }
+        catch (Exception ex)
+        {
+            StatusMessage = $"Error listing stacks: {ex.Message}";
+        }
+        finally
+        {
+            IsBusy = false;
+        }
+    }
+
+    [RelayCommand]
+    private async Task InspectInstanceAsync()
+    {
+        if (SelectedInstance == null) return;
+        if (SelectedSshHost == null && SelectedInstance.SshHost == null)
+        {
+            StatusMessage = "No SSH host associated with this instance.";
+            return;
+        }
+
+        IsBusy = true;
+        try
+        {
+            var host = SelectedInstance.SshHost ?? SelectedSshHost!;
+            var dockerCli = _services.GetRequiredService<SshDockerCliService>();
+            dockerCli.SetHost(host);
+
+            var services = await dockerCli.InspectStackServicesAsync(SelectedInstance.StackName);
+            SelectedServices = new ObservableCollection<ServiceInfo>(services);
+            StatusMessage = $"Found {services.Count} service(s) in stack '{SelectedInstance.StackName}'.";
+        }
+        catch (Exception ex)
+        {
+            StatusMessage = $"Error inspecting: {ex.Message}";
+        }
+        finally
+        {
+            IsBusy = false;
+        }
+    }
+
+    [RelayCommand]
+    private async Task DeleteInstanceAsync()
+    {
+        if (SelectedInstance == null) return;
+
+        IsBusy = true;
+        StatusMessage = $"Deleting {SelectedInstance.StackName}...";
+        try
+        {
+            var host = SelectedInstance.SshHost ?? SelectedSshHost;
+            if (host == null)
+            {
+                StatusMessage = "No SSH host available for deletion.";
+                return;
+            }
+
+            // Wire up SSH-based docker services
+            var dockerCli = _services.GetRequiredService<SshDockerCliService>();
+            dockerCli.SetHost(host);
+            var dockerSecrets = _services.GetRequiredService<SshDockerSecretsService>();
+            dockerSecrets.SetHost(host);
+
+            using var scope = _services.CreateScope();
+            var instanceSvc = scope.ServiceProvider.GetRequiredService<InstanceService>();
+
+            var result = await instanceSvc.DeleteInstanceAsync(SelectedInstance.Id);
+            StatusMessage = result.Success
+                ? $"Instance '{SelectedInstance.StackName}' deleted."
+                : $"Delete failed: {result.ErrorMessage}";
+
+            await LoadInstancesAsync();
+        }
+        catch (Exception ex)
+        {
+            StatusMessage = $"Error deleting: {ex.Message}";
+        }
+        finally
+        {
+            IsBusy = false;
+        }
+    }
+}