Establishes the main branch so feature branches have a base to merge
into. The repository was created empty, so main did not exist and no pull
request could target it.
This commit is deliberately empty. Nothing lands on main without review
(CLAUDE.md 10.2); it exists only so that m0/bootstrap has somewhere to be
merged from.
Co-Authored-By: Claude Code <noreply@anthropic.com>
