beamer: org-beamer-frame-default-options allowframebreaks (proper way)

NOT renewenvironment{frame} — that hack eats frame titles on H:2.
ox-beamer natively adds options to each frame it generates.

config.el

@@ -412,6 +412,11 @@ Skip for beamer exports — beamer uses adjustbox on plain tabular."
 
 (add-hook 'org-export-before-processing-hook #'my/org-ensure-tabularx-filter)
 
+;; Beamer: allowframebreaks on all frames (ox-beamer adds this to \begin{frame}[...])
+;; This is the proper way — NOT \renewenvironment{frame} which breaks frame titles.
+(with-eval-after-load 'ox-beamer
+  (setq org-beamer-frame-default-options "allowframebreaks"))
+
 ;; Optional: enable booktabs style (horizontal rules in tables)
 ;; (setq org-latex-tables-booktabs t)