(feat) add gateway assistant

gateway.proto

@@ -205,3 +205,67 @@ message SnapshotLoadResult {
     // a correlation ID to match up requests and responses. this field returns the contents of the request's msgID
     bytes msgID = 4;
 }
+
+
+// Assistant messages
+message AssistantRequest {
+    AssistantMessage message = 1;
+}
+
+message AssistantResponse {
+    AssistantMessage message = 1;
+}
+
+message AssistantMessage {
+    string id = 1;
+    google.protobuf.Timestamp  createdAt = 2;
+    string threadID= 3;
+    string status = 4;
+    google.protobuf.Timestamp  completedAt = 5;
+    string assistantID = 6;
+    repeated Content content = 7;
+    repeated Attachments attachments = 8;
+}
+
+message Content {
+    string type = 1;
+    oneof content {
+        Text text = 2;
+        ImageFile imageFile = 3;
+        ImageURL imageURL = 4;
+    }
+}
+
+message ImageFile {
+    string fileID = 1;
+    string detail = 2;
+}
+
+message ImageURL {
+    string url = 1;
+    string detail = 2;
+}
+
+message Text {
+    string text = 1;
+}
+
+message Attachments {
+    string fileID = 1;
+    repeated Tools tools = 2;
+}
+
+message Tools {
+    oneof tool {
+        CodeInterpreter codeInterpreter = 1;
+        FileSearch fileSearch = 2;
+    }
+}
+
+message CodeInterpreter {
+    string Type = 1;
+}
+
+message FileSearch {
+    string Type = 1;
+}