Adds _write_custodian_brief() to consistency_check.py. After every fix_repo()
run, a .custodian-brief.md is written to the repo root with: domain, last-synced
timestamp, current repo goal, active workstreams with progress (done/total), and
the first 7 open tasks per workstream (blocked → in_progress → todo order) with
task IDs. The file is git-committed when content changes so remote workers (e.g.
CoulombCore) can pull it and orient without a live MCP connection.
Session protocol template and CLAUDE.md updated: read .custodian-brief.md first,
then call get_domain_summary() as an enhancement (skip if MCP unreachable).
This eliminates false "State hub is offline" alarms in subagents and remote workers.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>