Generalizes the berachain beacon-kit init pattern into cometbft-common.sh (sourced
helper lib) so morph-node, gaiad/cosmos batch, shibarium and the EVM-cosmos chains
(haqq/sei/zero-gravity) become thin init.sh overrides. Validated against the real
init flows of beacon-kit, haqq, sei, zero-gravity. README.cometbft.md documents the
pattern (per-chain Dockerfile + thin init.sh + context). berachain stays on its own
beacon-kit.yml (untouched).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
