fix(docs): keep copy button fixed in horizontally scrollable code blocks

[DraXx-Van]

Fixes #16293

Summary:

• Wrap each pre element in a .code-block-wrapper container
• Move copy button positioning to the wrapper instead of the scrollable pre element
• Update hover selector to target the wrapper

Result:
The copy button now remains fixed in the top-right corner while horizontally scrolling code blocks.

Tested:

• Copy button appears on hover
• Copy functionality still works
• Button remains fixed during horizontal scrolling
• Verified on actual Mongoose docs pages using browser overrides

[Copilot]

Pull request overview

This PR fixes a UI issue in the Mongoose documentation site where the “copy code” button drifts/misaligns when horizontally scrolling within code blocks, by moving the button out of the scrollable <pre> element and anchoring it to a new non-scroll wrapper.

Changes:

• Wrap each <pre> in a new .code-block-wrapper container and attach the copy button to that wrapper.
• Move the “position: relative” anchoring from inline JS styling to a dedicated CSS rule on .code-block-wrapper.
• Update the hover selector so the button shows when hovering the wrapper rather than the <pre>.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
docs/js/copy-code.js	Wraps each <pre> in a .code-block-wrapper and appends the copy button to the wrapper so it doesn’t scroll with the code content.
docs/css/copy-code.css	Adds wrapper positioning and updates the hover selector to target the wrapper for correct button reveal behavior.