v1.9.0

Features

• YCS sidebar mount option - Toggle between Main and Sidebar mounts (into YouTube's #secondary-inner), with a sidebarByDefault opt-in and compact styling while docked (#155)
• Auto-expand reply context - New opt-in autoExpandReplyContext setting auto-renders parent comment chains above every reply on initial render and after every Show more, using a deferred + chunked scheduler to avoid main-thread freezes (#150)