Add v0.3.1 backwards compatibility tests for `StorableBuilder` and `KeyObfuscator`#45

tnull merged 2 commits intolightningdevkit:mainlightningdevkit/vss-client:mainfrom

tnull:2025-10-add-backwards-compat-teststnull/vss-client:2025-10-add-backwards-compat-testsCopy head branch name to clipboard