feat: quiz page question rework (#181)

- Replace Bootstrap accordion with flat card list for questions
- Add HTML5 drag-and-drop reordering with placeholder-between-cards UX
  and amber/green/red save status indicator next to the heading
- Add edit button per question opening a Bootstrap modal (bo--modal-form
  Stimulus controller with X-Modal-Request header pattern)
- Show read-only view button instead of edit for locked/finalized quizzes
- Add BankQuestion edit modal in question bank tab using same infrastructure
- Move modal action buttons into modal-footer via <template data-modal-footer>
- Fix IS_AUTHENTICATED_FULLY 403: replace ROLE_USER with IS_AUTHENTICATED
  on all backoffice controllers and in security.yaml access_control

Dockerfile

@@ -32,7 +32,6 @@ RUN set -eux; \
 		opcache \
 		zip \
 		gd \
-		excimer \
 	;
 
 # https://getcomposer.org/doc/03-cli.md#composer-allow-superuser