Summary

• remove stale .solo-mise local-state rules from the checked-in Brigade managed gitignore block
• make apply_gitignore() collapse all complete known managed blocks into one regenerated Brigade block
• cover mixed current-plus-legacy managed blocks while preserving user rules outside managed blocks

Verification

• .venv/bin/python -m pytest tests/test_gitignore.py tests/test_init.py -q -> 29 passed
• .venv/bin/brigade doctor --target . -> passed
• git diff --check -> passed
• .venv/bin/python -m pytest -q -> 262 passed
• PYTHONPATH=$HOME/repos/content-guard/src python3 -m content_guard scan . --policy $HOME/repos/content-guard/policies/public-repo.json -> Clean, 67 files checked
• pre-push content guard -> Clean, 67 files checked

Dogfood

• surfaced by live brigade work run --target .
• run artifacts: .brigade/runs/20260526-230438-221a9235
• work session: .brigade/work/20260526-230438-reconcile-the-checked-in-gitignore-managed-block