Update go.mod module line, all require/replace directives, and every
.go import path from forge.lthn.ai/core/go-blockchain to
dappco.re/go/core/blockchain. Add replace directives to bridge
dappco.re paths to existing forge.lthn.ai registry during migration.
Update CLAUDE.md, README, and docs to reflect the new module path.
Co-Authored-By: Virgil <virgil@lethean.io>
SparseChainHistory returned a zero hash when the chain was empty,
which the daemon could not resolve. Send the genesis hash instead
so the peer can locate the fork point and respond with chain entries.
Co-Authored-By: Charon <charon@lethean.io>