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/CreateInstanceDto.cs

@@ -0,0 +1,41 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace OTSSignsOrchestrator.Core.Models.DTOs;
+
+public class CreateInstanceDto
+{
+    [Required, MaxLength(100)]
+    public string CustomerName { get; set; } = string.Empty;
+
+    /// <summary>Exactly 3 lowercase letters used to derive all resource names.</summary>
+    [Required, MaxLength(3), MinLength(3), RegularExpression("^[a-z]{3}$", ErrorMessage = "Abbreviation must be exactly 3 lowercase letters.")]
+    public string CustomerAbbrev { get; set; } = string.Empty;
+
+    /// <summary>SSH host to deploy to.</summary>
+    public Guid? SshHostId { get; set; }
+
+    /// <summary>Pangolin Newt ID (optional — tunnel service excluded if not provided).</summary>
+    [MaxLength(500)]
+    public string? NewtId { get; set; }
+
+    /// <summary>Pangolin Newt Secret (optional — tunnel service excluded if not provided).</summary>
+    [MaxLength(500)]
+    public string? NewtSecret { get; set; }
+
+    // ── CIFS / SMB credentials (optional — falls back to global settings) ──
+
+    [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; }
+}

OTSSignsOrchestrator.Core/Models/DTOs/DeploymentResultDto.cs

@@ -0,0 +1,13 @@
+namespace OTSSignsOrchestrator.Core.Models.DTOs;
+
+public class DeploymentResultDto
+{
+    public bool Success { get; set; }
+    public string StackName { get; set; } = string.Empty;
+    public string Message { get; set; } = string.Empty;
+    public string? Output { get; set; }
+    public string? ErrorMessage { get; set; }
+    public int ExitCode { get; set; }
+    public long DurationMs { get; set; }
+    public int ServiceCount { get; set; }
+}

OTSSignsOrchestrator.Core/Models/DTOs/TemplateConfig.cs

@@ -0,0 +1,8 @@
+namespace OTSSignsOrchestrator.Core.Models.DTOs;
+
+public class TemplateConfig
+{
+    public string Yaml { get; set; } = string.Empty;
+    public List<string> EnvLines { get; set; } = new();
+    public DateTime FetchedAt { get; set; } = DateTime.UtcNow;
+}

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; }
+}

OTSSignsOrchestrator.Core/Models/Entities/AppSetting.cs

@@ -0,0 +1,23 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace OTSSignsOrchestrator.Core.Models.Entities;
+
+/// <summary>
+/// Key-value application setting persisted in the local database.
+/// Sensitive values are encrypted at rest via DataProtection.
+/// </summary>
+public class AppSetting
+{
+    [Key, MaxLength(200)]
+    public string Key { get; set; } = string.Empty;
+
+    [MaxLength(4000)]
+    public string? Value { get; set; }
+
+    [Required, MaxLength(50)]
+    public string Category { get; set; } = string.Empty;
+
+    public bool IsSensitive { get; set; }
+
+    public DateTime UpdatedAt { get; set; } = DateTime.UtcNow;
+}

OTSSignsOrchestrator.Core/Models/Entities/CmsInstance.cs

@@ -0,0 +1,117 @@
+using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace OTSSignsOrchestrator.Core.Models.Entities;
+
+public enum InstanceStatus
+{
+    Deploying,
+    Active,
+    Error,
+    Deleted
+}
+
+public enum XiboApiTestStatus
+{
+    Unknown,
+    Success,
+    Failed
+}
+
+public class CmsInstance
+{
+    [Key]
+    public Guid Id { get; set; } = Guid.NewGuid();
+
+    [Required, MaxLength(100)]
+    public string CustomerName { get; set; } = string.Empty;
+
+    /// <summary>Exactly 3 lowercase letters used to derive all resource names.</summary>
+    [MaxLength(3)]
+    public string CustomerAbbrev { get; set; } = string.Empty;
+
+    [Required, MaxLength(100)]
+    public string StackName { get; set; } = string.Empty;
+
+    [Required, MaxLength(200)]
+    public string CmsServerName { get; set; } = string.Empty;
+
+    [Required, Range(1024, 65535)]
+    public int HostHttpPort { get; set; }
+
+    [Required, MaxLength(500)]
+    public string ThemeHostPath { get; set; } = string.Empty;
+
+    [Required, MaxLength(500)]
+    public string LibraryHostPath { get; set; } = string.Empty;
+
+    [Required, MaxLength(200)]
+    public string SmtpServer { get; set; } = string.Empty;
+
+    [Required, MaxLength(200)]
+    public string SmtpUsername { get; set; } = string.Empty;
+
+    /// <summary>
+    /// JSON array of placement constraints, e.g. ["node.labels.xibo==true"]
+    /// </summary>
+    [MaxLength(2000)]
+    public string? Constraints { get; set; }
+
+    [Required, MaxLength(500)]
+    public string TemplateRepoUrl { get; set; } = string.Empty;
+
+    [MaxLength(500)]
+    public string? TemplateRepoPat { get; set; }
+
+    public DateTime? TemplateLastFetch { get; set; }
+
+    [MaxLength(100)]
+    public string? TemplateCacheKey { get; set; }
+
+    public InstanceStatus Status { get; set; } = InstanceStatus.Deploying;
+
+    /// <summary>Encrypted Xibo admin username for API access.</summary>
+    [MaxLength(500)]
+    public string? XiboUsername { get; set; }
+
+    /// <summary>Encrypted Xibo admin password. Never logged; encrypted at rest.</summary>
+    [MaxLength(1000)]
+    public string? XiboPassword { get; set; }
+
+    public XiboApiTestStatus XiboApiTestStatus { get; set; } = XiboApiTestStatus.Unknown;
+
+    public DateTime? XiboApiTestedAt { get; set; }
+
+    public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+
+    public DateTime UpdatedAt { get; set; } = DateTime.UtcNow;
+
+    /// <summary>Soft delete marker.</summary>
+    public DateTime? DeletedAt { 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; }
+
+    /// <summary>Encrypted CIFS password. Never logged; encrypted at rest.</summary>
+    [MaxLength(1000)]
+    public string? CifsPassword { get; set; }
+
+    [MaxLength(500)]
+    public string? CifsExtraOptions { get; set; }
+
+    /// <summary>ID of the SshHost this instance is deployed to.</summary>
+    public Guid? SshHostId { get; set; }
+
+    [ForeignKey(nameof(SshHostId))]
+    public SshHost? SshHost { get; set; }
+
+    public ICollection<OperationLog> OperationLogs { get; set; } = new List<OperationLog>();
+}

OTSSignsOrchestrator.Core/Models/Entities/OperationLog.cs

@@ -0,0 +1,48 @@
+using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace OTSSignsOrchestrator.Core.Models.Entities;
+
+public enum OperationType
+{
+    Create,
+    Update,
+    Delete,
+    TestXibo,
+    TestIdP,
+    DeploymentStatus,
+    Other
+}
+
+public enum OperationStatus
+{
+    Pending,
+    Success,
+    Failure
+}
+
+public class OperationLog
+{
+    [Key]
+    public Guid Id { get; set; } = Guid.NewGuid();
+
+    public OperationType Operation { get; set; }
+
+    public Guid? InstanceId { get; set; }
+
+    [ForeignKey(nameof(InstanceId))]
+    public CmsInstance? Instance { get; set; }
+
+    [MaxLength(200)]
+    public string? UserId { get; set; }
+
+    public OperationStatus Status { get; set; } = OperationStatus.Pending;
+
+    /// <summary>Human-readable message. NEVER includes secret values.</summary>
+    [MaxLength(2000)]
+    public string? Message { get; set; }
+
+    public long? DurationMs { get; set; }
+
+    public DateTime Timestamp { get; set; } = DateTime.UtcNow;
+}

OTSSignsOrchestrator.Core/Models/Entities/SecretMetadata.cs

@@ -0,0 +1,21 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace OTSSignsOrchestrator.Core.Models.Entities;
+
+public class SecretMetadata
+{
+    [Key]
+    public Guid Id { get; set; } = Guid.NewGuid();
+
+    [Required, MaxLength(200)]
+    public string Name { get; set; } = string.Empty;
+
+    public bool IsGlobal { get; set; }
+
+    [MaxLength(100)]
+    public string? CustomerName { get; set; }
+
+    public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+
+    public DateTime? LastRotatedAt { get; set; }
+}

OTSSignsOrchestrator.Core/Models/Entities/SshHost.cs

@@ -0,0 +1,59 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace OTSSignsOrchestrator.Core.Models.Entities;
+
+/// <summary>
+/// Represents a remote Docker Swarm host accessible over SSH.
+/// SSH key paths or encrypted passwords are stored for authentication.
+/// </summary>
+public class SshHost
+{
+    [Key]
+    public Guid Id { get; set; } = Guid.NewGuid();
+
+    [Required, MaxLength(200)]
+    public string Label { get; set; } = string.Empty;
+
+    [Required, MaxLength(500)]
+    public string Host { get; set; } = string.Empty;
+
+    [Range(1, 65535)]
+    public int Port { get; set; } = 22;
+
+    [Required, MaxLength(100)]
+    public string Username { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Path to the SSH private key file on the local machine.
+    /// </summary>
+    [MaxLength(1000)]
+    public string? PrivateKeyPath { get; set; }
+
+    /// <summary>
+    /// Encrypted passphrase for the SSH key (if any). Protected by DataProtection.
+    /// </summary>
+    [MaxLength(2000)]
+    public string? KeyPassphrase { get; set; }
+
+    /// <summary>
+    /// Encrypted SSH password (if key-based auth is not used). Protected by DataProtection.
+    /// </summary>
+    [MaxLength(2000)]
+    public string? Password { get; set; }
+
+    /// <summary>
+    /// Whether to prefer key-based auth over password.
+    /// </summary>
+    public bool UseKeyAuth { get; set; } = true;
+
+    public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+
+    public DateTime UpdatedAt { get; set; } = DateTime.UtcNow;
+
+    /// <summary>Last time a connection was successfully tested.</summary>
+    public DateTime? LastTestedAt { get; set; }
+
+    public bool? LastTestSuccess { get; set; }
+
+    public ICollection<CmsInstance> Instances { get; set; } = new List<CmsInstance>();
+}