7a0cec4920
nvim defaults autoindent=on, so the indent inserted by Vim/Nvim after the <CR> we return was being doubled by our own indent prefix — pressing Enter on a sub-item produced a deeper-nested item instead of a same-level one. Detect any auto-indent mechanism (autoindent, smartindent, cindent, indentexpr) and let it own the indentation; otherwise add it ourselves so vim's noautoindent default still works. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>