What problem does this address?

Background removal could exist in both the new client-side media editing flow (WordPress/gutenberg#74333) and the existing Edit Media screen in the Media Library as a "remove background" option.

What is your proposed solution?

Add a “Remove background” action that:

• Provides a before/after preview and ability to revert
• Produces a transparent PNG (or preserves original format when possible)
• Optionally adds “Replace background” but could be reserved for a follow-up PR/future release

Integrate into:

• Gutenberg client-side media editing flow (primary)
• Media Library: Edit Media screen (secondary)