blossom-server 4.4.1 sometimes stored a wrong blob size (0 or partial).
4.x ignored it when serving; 6.x sends it as Content-Length, so those
blobs come back empty or truncated after migrating. Add
scripts/fix-blossom-sizes.py to correct sizes from the files on disk
(only for files that hash to their name) and document running it after
the upgrade. Found on a copy of podsteadr.atobitcoin.io's data: 4 of 25
blobs, all small txt/jpeg; every blob verified byte-for-byte afterwards.
Also set media.requirePubkeyInRule explicitly to silence v6's startup
warning.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>