Refactored orchestrator for staged file handling, added structured prompt support, adjusted Feishu file handling

cmd/bot/main.go

@@ -177,6 +177,24 @@ func runMessageChannel(ctx context.Context, cfg config.Config, engine *agent.Orc
 		}
 		lg.Infof("starting feishu transport")
 		return fs.Run(ctx, func(ctx context.Context, msg feishu.IncomingMessage) (string, error) {
+			if msg.MsgType == "file" && len(msg.FileBytes) > 0 {
+				content := msg.FileBytes
+				if msg.FilePath != "" {
+					if b, err := os.ReadFile(msg.FilePath); err == nil && len(b) > 0 {
+						content = b
+					} else if lg != nil {
+						lg.Warnf("read local file failed path=%s err=%v; fallback to in-memory bytes", msg.FilePath, err)
+					}
+				}
+				files := []llm.InputFile{{
+					FileName: msg.FileName,
+					MimeType: msg.FileMime,
+					Content:  content,
+				}}
+				// Feishu file event and user question are split into separate messages.
+				// Use empty text so file IDs are cached and consumed by the next text query.
+				return engine.HandleMessageWithFiles(ctx, msg.ChatID, msg.UserID, "", files)
+			}
 			return engine.HandleMessage(ctx, msg.ChatID, msg.UserID, msg.Text)
 		})
 	default: