Implement meeting assistant v1

MeetingAssistant/MeetingNotes/IMeetingArtifactStore.cs

@@ -0,0 +1,24 @@
+namespace MeetingAssistant.MeetingNotes;
+
+public interface IMeetingArtifactStore
+{
+    Task CreateAssistantContextAsync(
+        MeetingSessionArtifacts artifacts,
+        string agenda,
+        DateTimeOffset? scheduledEnd,
+        CancellationToken cancellationToken);
+
+    Task UpdateAssistantContextStateAsync(
+        MeetingSessionArtifacts artifacts,
+        AssistantContextState state,
+        CancellationToken cancellationToken);
+}
+
+public enum AssistantContextState
+{
+    Transcribing,
+    SpeakerRecognition,
+    Summarizing,
+    Finished,
+    Error
+}