Function render_builtin_tools_table 

pub fn render_builtin_tools_table() -> String

Render the built-in tools table (the markdown fenced by the doc markers).

One row per doc_group, in list order. Columns are padded to their widest cell so the output matches rumdl’s own table formatting, keeping the generated docs rumdl fmt --check-clean (the project config normalizes table column widths).