Constant GITATTRIBUTES_TEMPLATE 

const GITATTRIBUTES_TEMPLATE: &str = "\
# A blockworx container. revs/ holds the document at every rev and
# manifest.jsonl is the trail that names them.
#
# The merge driver named here is not built in. Define it once, globally:
#     git config --global merge.conflict-always.name 'never auto-merge'
#     git config --global merge.conflict-always.driver false
# Without it git falls back to the text merge, and a merged manifest will
# be refused by the integrity chain at load — loudly, but later.
manifest.jsonl merge=conflict-always
revs/** binary
assets/** binary
lock export-ignore
";

Two divergent manifest.jsonls are concurrent editing through the back door, which this design deliberately has no answer for, so the conflict is surfaced at merge time instead of waiting for a replay to refuse the result.