4 atomic tasks (3 commits + 1 verification+push) for installing brain-meta
plugins #17 and #18 per routing.md §5.1, bumping brain to v1.2 with
routing.md v1.1 (new task classes: plugin creation, hook creation).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>