ed25519 over checksums.txt: llmgw release keygen makes the pair, CI signs with the RELEASE_SIGNING_KEY secret when it is set, and release.Install refuses an unsigned or wrongly signed release when the build embeds a trusted key (internal/release/trusted.pub, empty for now) or LLMGW_RELEASE_KEY names one. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>