Add a global, site-wide language filter (e.g., English-only)

I would like the ability to set a global language filter that applies across the entire site. Right now, we can filter by language in lists and collections, but this preference doesn't carry over elsewhere. The biggest pain point with this is that I keep accidentally adding French cards to my cart, only finding out when reviewing just before purchasing. I purchase cards from the card detail page and then while navigating through user profiles.

Specifically, when I visit a card detail page or a user's profile, I want the system to respect my preference (for example, showing English cards only) and hide other languages (like French cards) automatically across all pages.