Prevent gallery clicks from scrolling preview to top

[apples-kksk]

Description

Prevent rendered gallery clicks from moving the preview document back to the top.

This PR:

• Adds a click handler for rendered gallery blocks.
• Preserves carousel click handling while preventing default hash-link navigation.
• Stops gallery arrow/thumbnail clicks from scrolling the preview to the top.

Validation:

• Ran: git diff --check.
• Not run: project ESLint/tests because dependencies are not installed in this checkout.

Issue fixed

Fixes #3021.

Type of changes

• 🔘 Bug fix (Change that fixed an issue)
• ⚪ Breaking change (Change that can cause existing functionality to change)
• ⚪ Improvement (Change that improves the code. Maybe performance or development improvement)
• ⚪ Feature (Change that adds new functionality)
• ⚪ Documentation change (Change that modifies documentation. Maybe typo fixes)

Checklist:

• 🔘 My code follows the project code style
• ⚪ I have written test for my code and it has been tested
• ⚪ All existing tests have been passed
• ⚪ I have attached a screenshot/video to visualize my change if possible
• 🔘 This PR will modify the UI or affects the UX
• ⚪ This PR will add/update/delete a keybinding