A mod index can now publish three optional per-entry fields -- downloads
(total across every release), first_release and last_release (ISO days) --
which the FIND MODS listing shows in the same gold line the MODS tab uses.
The fields are additive by design: feeds that carry them stay readable by
every build that predates them (schema_version stays 1), and feeds that do
not render exactly as before. ModUpdate.statsLine builds the shared line;
the MODS tab reuses it. Parser, formatting, and parse coverage are tested.
The MODS tab now shows each installed mod's total GitHub downloads
(summed asset download_count across all releases), its first and latest
release dates, and a Sort row (Name / Popularity / Release date /
Last updated) persisted in options.modSort.
The launcher already fetched per-repo release lists for update checks, so
the data rides the same cached fetch: parseRelease keeps download_count
and published_at, writeCache persists them, and a cache entry written
before the fields existed is treated as stale and refetched once instead
of hiding the line behind an old cache.