Restructure solution layout by module

src/Scanner/StellaOps.Scanner.WebService/Diagnostics/ServiceStatus.cs

@@ -0,0 +1,47 @@
+using System;
+
+namespace StellaOps.Scanner.WebService.Diagnostics;
+
+/// <summary>
+/// Tracks runtime health snapshots for the Scanner WebService.
+/// </summary>
+public sealed class ServiceStatus
+{
+    private readonly TimeProvider timeProvider;
+    private readonly DateTimeOffset startedAt;
+    private ReadySnapshot readySnapshot;
+
+    public ServiceStatus(TimeProvider timeProvider)
+    {
+        this.timeProvider = timeProvider ?? throw new ArgumentNullException(nameof(timeProvider));
+        startedAt = timeProvider.GetUtcNow();
+        readySnapshot = ReadySnapshot.CreateInitial(startedAt);
+    }
+
+    public ServiceSnapshot CreateSnapshot()
+    {
+        var now = timeProvider.GetUtcNow();
+        return new ServiceSnapshot(startedAt, now, readySnapshot);
+    }
+
+    public void RecordReadyCheck(bool success, TimeSpan latency, string? error)
+    {
+        var now = timeProvider.GetUtcNow();
+        readySnapshot = new ReadySnapshot(now, latency, success, success ? null : error);
+    }
+
+    public readonly record struct ServiceSnapshot(
+        DateTimeOffset StartedAt,
+        DateTimeOffset CapturedAt,
+        ReadySnapshot Ready);
+
+    public readonly record struct ReadySnapshot(
+        DateTimeOffset CheckedAt,
+        TimeSpan? Latency,
+        bool IsReady,
+        string? Error)
+    {
+        public static ReadySnapshot CreateInitial(DateTimeOffset timestamp)
+            => new ReadySnapshot(timestamp, null, true, null);
+    }
+}