mcpg-plugin-backend-net-core

Shared HTTP-over-reqwest core for mcpg's network backend plugins (http, grpc, graphql). Owns the per-credential reqwest::Client cache (ClientRegistry), the DNS-rebinding / SSRF guard (build_http_client), the per-call request/response execution primitives (exec), and the reusable downstream-error retry-guidance shaping (retry). A pure rlib — it is NOT a loadable plugin (no plugin.yaml); the network backend cdylibs link it at build time so the security-sensitive SSRF guard lives in exactly one place.