V26 fixes the confirmed 413 oversized-checkpoint failure. It keeps the same local recovery and same-origin bridge, but splits each season-end upload into about 4 MB immutable shards. A small manifest is written after the shards, and the public state is written LAST.
V26 reads the existing V24/V25 IndexedDB progress directly, so the currently saved S83 W10 checkpoint is recovered without rescraping it.
Drag this button to the Edge favourites/bookmarks bar (your existing bookmark can remain if it already loads gb-youth-club-top10-live.js):
Uses only GB_YOUTH_CLUB_DATA. Does not read or write GB_MAXI_DATA.