Adds a clickable info icon next to the "For You" title that displays a popover explaining the feed's filtering logic ("Most Recent Video - Disinterests Tags - Watch History + Interests Tags"). Implemented as a reusable helper `attachFeedInfoPopover` in `js/ui/components/FeedInfoPopover.js` to support future use on other feed pages. Updated `views/for-you.html` and `js/forYouView.js` to integrate the new component. Verified with Playwright.
