The UpdateMediaItem SQL query only SET 23 of 37 media_items columns,
causing all 3 call sites (admin PUT, bulk update, force rescan) to
silently NULL out the 14 unwired fields on every update.
Added: manga_type, reading_direction, series_count, volume, imprint,
age_rating, web_url, metadata_notes, community_rating, story_arc,
is_black_and_white, alternate_info, scan_information, summary.
Regenerated sqlc Go code (queries.sql.go) with 37-param
UpdateMediaItemParams struct.