fix(admin): complete processing diagnostics and failure evidence

JobTrackerApi/Services/OperationEventLog.cs

@@ -14,11 +14,13 @@ public static class OperationEventLog
     public static string? SafeStage(string? value) => value is "cv_validating_file" or "cv_extracting" or "cv_identifying_sections"
         or "cv_analysing" or "cv_validating_details" or "cv_preparing_review" or "cv_review_ready" ? value : null;
 
-    public static string? SafeFailure(string? value) => value is null ? null : value is
-        "timeout" or "lease_expired" or "deadline_exceeded" or "entitlement_changed" or "document_unavailable"
-        or "sidecar_unavailable" or "upstream_unavailable" or "invalid_response" or "circuit_open" or "rate_limited"
-        or "permission_denied" or "cancelled" or "upload_rejected" or "parser_failed" or "malformed_output" or "provider_unavailable"
-        ? value : "processing_failed";
+    public static IReadOnlyList<string> FailureCodes { get; } = Array.AsReadOnly(new[]
+    {
+        "timeout", "lease_expired", "deadline_exceeded", "entitlement_changed", "document_unavailable",
+        "sidecar_unavailable", "upstream_unavailable", "invalid_response", "circuit_open", "rate_limited",
+        "permission_denied", "cancelled", "upload_rejected", "parser_failed", "malformed_output", "provider_unavailable",
+    });
+    public static string? SafeFailure(string? value) => value is null ? null : FailureCodes.Contains(value, StringComparer.Ordinal) ? value : "processing_failed";
 
     public static UserOperationEvent Create(UserOperation operation, OperationEventKind kind, DateTime now,
         string? status = null, string? stage = null, string? failure = null, int? attempt = null) => new()