initial work on message history and data transfer

crates/shared/proto/api.proto

@@ -7,13 +7,17 @@ service AiDaemon {
   rpc ChatHistory(ChatHistoryRequest) returns (ChatHistoryResponse);
 }
 
-message ChatResponse {
+message ChatMessage {
   int64 id = 1;
-  int64 chat_id = 2;
   string text = 10;
   bool is_user = 20;
 }
 
+message ChatResponse {
+  int64 chat_id = 2;
+  repeated ChatMessage messages = 10;
+}
+
 message ChatRequest {
   optional int64 chat_id = 1;
   optional string text = 10;