Fixed: cdn-renderer styles.css now collapses to a single column for
artifacts without a TOC sidebar (type=decision, task, briefing). The
.cycle-body grid was applying its 200px sidebar slot unconditionally,
landing <main> in the narrow column for non-cycle types.

Added: examples/decision-example.md as a reference type=decision artifact
and cross-type rendering regression.

Docs: CHANGELOG.md tracking spec + renderer releases (Keep-a-Changelog
format).