Phase 0 exploration for alknet-http (greenfield crate, no existing arch):
HTTP server (axum, ProtocolHandler for h2/http1.1, h3 deferred), HTTP client
(reqwest, the from_openapi/from_mcp forwarding handlers), MCP streamable HTTP
(feature-gated, stdio excluded as security position), to_openapi/to_mcp
projections.
Records: 8 design points (DH-3 HTTP→call operation mapping as the load-bearing
one), the settled adapter location map (from alknet-call gap analysis), the
no-env-vars invariant (Capabilities → from_openapi handler → HTTP header as the
credential injection point), and the prerequisite on alknet-call's
OperationAdapter trait being defined first.