The SDK accepted any number as apiVersion while the host refuses anything
but a positive integer no newer than its plugin API, a false green for an
author. The manifest patterns, sets and caps now live in the host's
protocol/manifest-rules.ts, and gen-plugin-facts writes them and
PLUGIN_API_VERSION into the SDK, so check:plugin-facts covers them. One
manifest corpus is judged by both validators in a server test (the SDK may
only be stricter, case by case), and a typecheck test holds the SDK's plugin
API types to the host child's copy, which gains rawBodyBase64.
Maurice