Replaces the hand-rolled channel search list and the flat tag chip walls with the
searchable, ARIA-correct Combobox built for the Plex filter bar (E5), so the YT feed
filters get the same input+listbox+chips UX with facet counts.
- ChannelPicker now wraps Combobox (selectedLabels keeps picks named); drops its bespoke
input + scroll-fade list.
- Sidebar language/topic/tags: each Combobox owns only its slice of the shared
filters.tags list (setTagSelection replaces that list's ids, leaves the rest). Topic
keeps its any/all match toggle, Your tags keeps Manage. TagChip removed.
peter
ad0cf5827b