Hardcode Cloud trial CTA in docs right gutter

[KOTungseth]

Description

To drive higher conversion from technical documentation, we are moving from an experimental Optimizely implementation to a hardcoded "Start free trial" CTA. This button should appear on all documentation pages within the right gutter, positioned to capture user interest without obstructing core technical utilities.

Proposed UI structure

The CTA should be inserted between the version selector and Docs utility buttons.

Proposed gutter order:

Version dropdown selector
Start free trial CTA button

--Horizontal rule--
View as Markdown button
Report an issue button
Edit this page button
Learn how to contribute button

--Horizontal rule--
On this page (TOC)

Technical requirements

• Location: Modify the sidebar in docs-builder to include the new CTA.
• Tracking: Ensure the button includes the standard tracking from docs pages -> https://cloud.elastic.co/registration?page=docs&placement=docs-body
• Responsive behavior:
  • Ensure the button maintains appropriate padding/margins on tablet views.
  • Confirm if the button should remain visible or be hidden when the gutter collapses on mobile/small screens.

Stakeholders

• Design: @natalia (for final CSS/padding specs)
• Verification: @christian (tracking validation)

References

CTA button design

[itsalexcm]

I have worked on the design and development of this. You can find the PR here: Add trial CTA card to article sidebar#2721