Introduce ~org-smart-line-beginning~ to avoid issues

Folded regions confuse the canonical implementation of
smart-line-beginning

global.org

@@ -763,10 +763,17 @@
     where I would not want to use this feature). Also, disable
  ~truncate-lines~
     #+begin_src emacs-lisp
+      ;; assume that we are in a folded headline; move back to heading
+      ;; otherwise we will be trapped in the invisible region
       (add-hook 'org-mode-hook 'turn-on-auto-fill)
+      (defun org-smart-line-beginning ()
+        (interactive)
+        (when (invisible-p (point))
+          (org-back-to-heading))
+        (smart-line-beginning))
+      (define-key org-mode-map (kbd "C-a") 'org-smart-line-beginning)
       (setq org-starting-truncated nil
             org-startup-folded t)
-
     #+end_src
 *** Cosmetics
     Change the default ellipsis ~...~ to the unicode ellipsis ~…~