2.1 Configuration POCOs (Mqtt, Storage, UrlFetch, ApiKey)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/FrameProcessor/Configuration/MqttOptions.cs

@@ -0,0 +1,35 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace FrameProcessor.Configuration;
+
+/// <summary>
+/// Bound from the <c>Mqtt</c> section of <c>appsettings.json</c>. See SPEC.md §6.1.
+/// </summary>
+public sealed class MqttOptions
+{
+    public const string SectionName = "Mqtt";
+
+    [Required(AllowEmptyStrings = false)]
+    public string Host { get; set; } = string.Empty;
+
+    [Range(1, 65535)]
+    public int Port { get; set; } = 1883;
+
+    [Required(AllowEmptyStrings = false)]
+    public string ClientId { get; set; } = string.Empty;
+
+    public string? Username { get; set; }
+
+    public string? Password { get; set; }
+
+    public bool UseTls { get; set; }
+
+    [Required(AllowEmptyStrings = false)]
+    public string BaseTopic { get; set; } = "frames";
+
+    [Range(0, 2)]
+    public int PublishQos { get; set; } = 1;
+
+    [MinLength(1)]
+    public int[] RetryBackoffSeconds { get; set; } = Array.Empty<int>();
+}