v4.0.1 — day-one field fixes for the v4 environment
Patch folded back from the environment's first real installs. Hooks generated by kj harden now chain the machine's previous global hooks (personal guards keep applying, real exit code preserved), and branch-first is both ordered and enforced: explicit playbook step + pre-commit guard rejecting direct commits on the configured base branch (KJ_ALLOW_BASE_COMMIT=1 to override). Full notes in the CHANGELOG.