The Cloudflare Workers env record. There is no ambient environment on
the edge, so without this runtime.env is empty on Workers and
ConfigPlugin reads nothing.
Pass what the platform provides — import { env } from 'cloudflare:workers'
— and only its string entries populate runtime.env. Object bindings
(KV, R2, D1, …) are published separately by CloudflarePlugin under
CAPABILITIES.CLOUDFLARE, because IRuntimeServices.env is contracted as
a string record.
Ignored on Deno, Node, and Bun.