The floating header band already centres on --content-mw (the width the
page's cards use), but its search box + scope-toggle/sync-chip group was
packed to the left edge (default justify-start), leaving it offset from
the centred card grid on max-width pages (Plex/Channels/Playlists).
Add justify-center to the band so the group centres within it: once the
column is wider than the box's max-w, the box sits centred over the
cards instead of hugging the left edge. Shared header row, so it applies
to every module with a SearchBar. Verified at 1920px on Plex: group
centre == content-band centre (431px margin each side).
peter
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