Rows now span the full page width and show track duration plus
listens count, matching the columns already used elsewhere in the
app. Also trims the trailing bottom padding to match other pages.
Home and explore had an oversized trailing bottom padding compared to
the rest of the app; brought both down to match. Also matches "Mis
listas" grid/limit on home to "Novedades", and sizes the library page
header the same as the playlists page header.
Move authenticated pages under an (app) group with a Sidebar shell, add /auth/login and page-based /login, drop the old explore page and login +server endpoint, and add the server upload helper.
Admin