Rendering every article per request is expensive. Bodies are now
RAM-cached keyed by the public base URL and cleared from
_invalidate_pages (the same hook that drops the page render cache on
any content/settings write). Responses carry a blake3 content-hash
ETag and answer 304, so polling feed readers revalidate cheaply;
matching page behavior, 304 revalidations are not recorded in
analytics.
LeoVasanko