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.Core/Models/DTOs/UpdateInstanceDto.cs

@@ -0,0 +1,43 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace OTSSignsOrchestrator.Core.Models.DTOs;
+
+public class UpdateInstanceDto
+{
+    [MaxLength(500)]
+    public string? TemplateRepoUrl { get; set; }
+
+    [MaxLength(500)]
+    public string? TemplateRepoPat { get; set; }
+
+    [MaxLength(200)]
+    public string? SmtpServer { get; set; }
+
+    [MaxLength(200)]
+    public string? SmtpUsername { get; set; }
+
+    public List<string>? Constraints { get; set; }
+
+    [MaxLength(200)]
+    public string? XiboUsername { get; set; }
+
+    [MaxLength(200)]
+    public string? XiboPassword { get; set; }
+
+    // ── CIFS / SMB credentials (per-instance) ──
+
+    [MaxLength(200)]
+    public string? CifsServer { get; set; }
+
+    [MaxLength(500)]
+    public string? CifsShareBasePath { get; set; }
+
+    [MaxLength(200)]
+    public string? CifsUsername { get; set; }
+
+    [MaxLength(500)]
+    public string? CifsPassword { get; set; }
+
+    [MaxLength(500)]
+    public string? CifsExtraOptions { get; set; }
+}