Implement reversible Sentinel beta foundation

src/OCSentinelCli/AttackScanner.cs

@@ -34,6 +34,7 @@ internal sealed class AttackScanner
         ScanExchangeLogons(attacks, errors, since);
         ScanIisFtpLogs(attacks, errors, since, configuration);
         ScanFileZillaLogs(attacks, errors, since, configuration);
+        RansomwareBetaSummary ransomwareBeta = RansomwareBetaDetector.Scan(configuration, errors);
 
         if (configuration.ExcludedIps.Count > 0)
         {
@@ -53,7 +54,7 @@ internal sealed class AttackScanner
             .ToList();
 
         int uniqueIpCount = attacks.Select(static attack => attack.SourceIp).Distinct(StringComparer.OrdinalIgnoreCase).Count();
-        AlertAssessment baseAssessment = AssessAttackActivity(attacks, uniqueIpCount, configuration);
+        AlertAssessment baseAssessment = MergeRansomwareAssessment(AssessAttackActivity(attacks, uniqueIpCount, configuration), ransomwareBeta);
         string baseAlertState = baseAssessment.State;
         string baseAlertReason = baseAssessment.Reason;
         VulnerabilityCorrelationSummary vulnerabilityCorrelation = string.IsNullOrWhiteSpace(options.VulnerabilityCsvPath)
@@ -79,6 +80,7 @@ internal sealed class AttackScanner
             BaseAlertState = baseAlertState,
             BaseAlertReason = baseAlertReason,
             VulnerabilityCorrelation = vulnerabilityCorrelation,
+            RansomwareBeta = ransomwareBeta,
             Runtime = new ScanRuntimeMetadata
             {
                 StartedAtUtc = startedAtUtc,
@@ -517,6 +519,27 @@ internal sealed class AttackScanner
         return new AlertAssessment("ok", $"Low-volume login errors observed: events={attacks.Count}, unique IPs={uniqueIpCount}; no burst or password-spraying pattern detected.");
     }
 
+    private static AlertAssessment MergeRansomwareAssessment(AlertAssessment loginAssessment, RansomwareBetaSummary ransomwareBeta)
+    {
+        if (ransomwareBeta.State is not ("warning" or "critical"))
+        {
+            return loginAssessment;
+        }
+
+        int loginPriority = AlertPriority(loginAssessment.State);
+        int ransomwarePriority = AlertPriority(ransomwareBeta.State);
+        string state = ransomwarePriority > loginPriority ? ransomwareBeta.State : loginAssessment.State;
+        string reason = $"{loginAssessment.Reason} {ransomwareBeta.Reason}";
+        return new AlertAssessment(state, reason);
+    }
+
+    private static int AlertPriority(string state) => state switch
+    {
+        "critical" => 2,
+        "warning" => 1,
+        _ => 0
+    };
+
     private static int GetPeakEventCount(IReadOnlyList<AttackEvent> events, TimeSpan window)
     {
         int start = 0;