Main changes:

-- Watching course chunks can fuel the Time Bank, but only after continuous 5-minute watch time.
-- Time Bank can be turned on to unlock YouTube recommendations and comments.
-- When Time Bank is off or expired, recommendations and comments are hidden again.
-- Time Bank now strictly expires to 0 instead of keeping stale leftover state.
-- Hidden recommendations/comments keep their layout space, so the YouTube player should not shift to the center.
-- Added an optional fuel link button that opens a sample page; staying there for 15 seconds adds Time Bank fuel.
-- Saved videos now include a direct open-video link in the watch list.
-- Video title fetching is more reliable.
-- Added popup text explaining: “Continuous 5 min watch is eligible for Time Bank reward.”
-- Added required support for dynamic script/CSS injection so restrictions continue working after YouTube navigation/reloads.