fix: proxyHandler — io.Copy вместо ручного цикла

server/main.go

@@ -327,30 +327,12 @@ func proxyHandler(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/octet-stream")
 	w.Header().Set("Last-Modified", stat.LastModified.Format(http.TimeFormat))
 
-	buf := make([]byte, 64*1024) // 64KB buffer
-	flusher, canFlush := w.(http.Flusher)
-	written := int64(0)
-	for {
-		n, readErr := obj.Read(buf)
-		if n > 0 {
-			nw, writeErr := w.Write(buf[:n])
-			if writeErr != nil {
-				log.Printf("Error writing response: %v", writeErr)
-				return
-			}
-			written += int64(nw)
-			if canFlush {
-				flusher.Flush()
-			}
-		}
-		if readErr != nil {
-			if readErr != io.EOF {
-				log.Printf("Error reading object: %v", readErr)
-			}
-			break
-		}
+	written, err := io.Copy(w, obj)
+	if err != nil {
+		log.Printf("Error streaming object: %v (sent %d/%d bytes)", err, written, stat.Size)
+	} else {
+		log.Printf("Proxy: sent %d bytes for %s", written, key)
 	}
-	log.Printf("Proxy: sent %d/%d bytes for %s", written, stat.Size, key)
 }
 
 func discoveryHandler(w http.ResponseWriter, r *http.Request) {