adcea02e85
Three coupled changes to /implement: - Boss-context offload via single subagent dispatch (target ~100x reduction) - Iter isolation via branches (eliminates parallel-implementer conflicts) - Per-iter journals under docs/journals/ replacing the JOURNAL.md monolith JOURNAL.md becomes docs/journal-archive.md at acceptance time. Workers stay at Opus 4.7; saving comes from token-volume relocation only.