Add resilient upload queue and client health

src/OCSentinelCli/Models.cs

@@ -136,6 +136,16 @@ internal sealed record ScanRuntimeMetadata
     public DateTimeOffset FinishedAtUtc { get; init; }
 
     public bool UploadAttempted { get; init; }
+
+    public bool UploadSucceeded { get; init; }
+
+    public string UploadStatus { get; init; } = "not-attempted";
+
+    public int QueuedReportCount { get; init; }
+
+    public DateTimeOffset? LastSuccessfulUploadUtc { get; init; }
+
+    public string LastUploadError { get; init; } = string.Empty;
 }
 
 internal sealed record VulnerabilityFinding