Neovim textwidth plus treesitter indentexpr mangles prose wrapping

In a soft-wrap Neovim setup (wrap, linebreak, gj/gk mappings), a FileType autocmd setting textwidth=80 for typst/markdown makes Neovim insert hard newlines while you type. If treesitter indentexpr is also set for every filetype, each hard-wrapped line gets an inconsistent indent (some deeper, some at column 0), which looks like random formatting. Fix: remove textwidth for prose filetypes and set breakindent=true so soft-wrapped lines align with their line's indent. Lines that were already hard-wrapped need rejoining manually (vipJ).