Make entire collapsible heading clickable for better UX

[virgile-dev]

Enhancement Request

Is your feature request related to a problem or unsupported use case? Please describe.
Currently, in collapsible heading / paragraphs, only the small black triangle icon is clickable to expand or collapse the content. This creates a poor user experience as users must precisely aim their cursor to interact with the heading. This is especially problematic for users with accessibility needs or those using touch devices.

Describe the solution you'd like
I propose making the entire heading text clickable to expand or collapse the paragraph, while preserving the following behaviors:

• In reading mode: The entire heading acts as a clickable button to toggle the content visibility.
• In editing mode: The heading remains fully editable, with the cursor placement working as expected.

This change would improve usability and accessibility without disrupting the editing workflow. The small triangle icon can remain for visual consistency but won't be the sole interactive element.