TUI::Markdown::Layout

Turns a width-agnostic Array(Block) into flattened physical rows — one Array(InlineRun) per row actually drawn to the screen — by applying block-specific indent/marker/border rules and running Wrap.wrap wherever reflow is appropriate (paragraphs, list items, blockquotes; NOT code blocks, which stay verbatim since rewrapping code would change its meaning; NOT table cells, which truncate instead — see Config#table_max_col_width).