Harden speaker identity samples

MeetingAssistant/MeetingAssistantOptions.cs

@@ -293,6 +293,10 @@ public sealed class SpeakerIdentificationOptions
 
     public int MaxSnippetsPerSpeaker { get; set; } = 3;
 
+    public TimeSpan MinimumSampleSpeechDuration { get; set; } = TimeSpan.FromSeconds(30);
+
+    public TimeSpan MaximumSampleSegmentGap { get; set; } = TimeSpan.FromSeconds(1);
+
     public double SilenceBetweenSnippetsSeconds { get; set; } = 1;
 
     public TimeSpan LiveSampleBufferDuration { get; set; } = TimeSpan.FromMinutes(10);
@@ -302,6 +306,23 @@ public sealed class SpeakerIdentificationOptions
     public TimeSpan MatchTimeout { get; set; } = TimeSpan.FromMinutes(3);
 
     public AzureSpeechOptions AzureSpeech { get; set; } = new();
+
+    public SpeakerIdentityPyannoteValidationOptions PyannoteValidation { get; set; } = new();
+}
+
+public sealed class SpeakerIdentityPyannoteValidationOptions
+{
+    public bool Enabled { get; set; }
+
+    public double MinimumSingleSpeakerCoverage { get; set; } = 0.90;
+
+    public double MinimumMatchingKnownSnippetRatio { get; set; } = 0.50;
+
+    public PyannoteDiarizationOptions Diarization { get; set; } = new()
+    {
+        Enabled = true,
+        AlignmentMode = PyannoteAlignmentMode.PyannoteTurns
+    };
 }
 
 public sealed class AgentOptions