Background-session edits were being forced into an isolated git worktree,
defaulting to a branch off origin/master -- which has none of this
branch's FABRIC.md content -- conflicting with this repo's subversion-
style workflow (commit directly to the working branch, no side branches
without explicit permission). Sets worktree.bgIsolation: none so
background-session edits land directly in the shared checkout, consistent
with the existing CLAUDE.md policy.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
