All reading list links point at external http(s) URLs, so each rendered
anchor now carries rel="noopener noreferrer" as a hardening best
practice. Renderer test updated for the new attribute and asserts every
rendered link carries it.
Renders the data file as category-grouped HTML. Pure string builder with
guarded browser wiring so it is unit-testable in Node; escapes all text,
skips invalid entries, and handles duplicate category slugs.
bot-implementer
bot-implementer