Add a workspace-level toggle to enable/disable the Co-authored-by
trailer for agent commits. Default is enabled (on).
Backend:
- Include workspace settings in daemon register response
- Store settings in daemon workspaceState
- Thread CoAuthoredByEnabled through WorktreeParams to conditionally
install the prepare-commit-msg hook
- Parse co_authored_by_enabled from workspace settings JSONB
Frontend:
- Replace empty Labs tab placeholder with a Git section containing
a Switch toggle for the Co-authored-by trailer setting
- Optimistically update the workspace query cache on toggle