Changelog 2026-03-05 (Accessibility Homepage Section Semantics Pass 5)

Changed

• Added an explicit label to homepage sidebar: aria-label="Site updates and navigation".
• Converted homepage sidebar cards from generic <div> wrappers to semantic <section> regions.
• Added heading associations (aria-labelledby) to key cards (Now shipping, Monthly review, Latest changelog, Now building, Quick links).
• Preserved existing visual layout and content while improving assistive-technology landmark parsing.

Why

• Continue the accessibility sweep by strengthening semantic structure and section navigation on the homepage.