Fix race condition crash in timeout middleware

- Remove duplicate http.Error call when context times out
- The timeout middleware already handles writing the response
- Prevents "concurrent write to websocket connection" panic

internal/server/handlers.go

@@ -248,8 +248,7 @@ func (s *Server) handleStats() http.HandlerFunc {
 		select {
 		case <-ctx.Done():
 			s.logger.Error("Database stats timeout")
-			http.Error(w, "Database timeout", http.StatusRequestTimeout)
-
+			// Don't write response here - timeout middleware already handles it
 			return
 		case err := <-errChan:
 			s.logger.Error("Failed to get database stats", "error", err)