feat(http): implement to_mcp 4-tool gateway projection (rmcp ServerHandler, StreamableHttpService at /mcp)
to_mcp is the MCP-direction gateway projection (ADR-041): exposes 4 fixed
gateway tools (search, schema, call, batch) over rmcp StreamableHttpService
nested into the axum Router at /mcp, not one MCP tool per registry operation.
The LLM discovers operations on demand via search+schema.
- ToMcpGateway implements rmcp ServerHandler (call_tool, list_tools, get_info)
- tools/list returns the 4 fixed gateway tools, never the registry's ops
- search dispatches services/list via GatewayDispatch::invoke, excludes
Subscription ops (ADR-041 §2), returns names + descriptions
- schema dispatches services/schema, returns the full OperationSpec
- call dispatches via GatewayDispatch::invoke (shared spine), maps
ResponseEnvelope -> CallToolResult::structured (Ok) /
CallToolResult::structured_error (Err(CallError))
- batch loops over invoke, returns an array of results
- Bearer auth via shared bearer_auth_middleware applied around nest_service
(rmcp simple_auth_streamhttp pattern); Identity read from
RequestContext.extensions -> http::request::Parts.extensions
(research §6 #2 identity-survives-framing assumption, confirmed via test)
- to_mcp is a pure projection (consumes registry, produces no entries)
- Feature-gated behind mcp; stdio NOT built (ADR-037)
- /mcp route wired in adapter.rs replacing the placeholder 501
cargo test -p alknet-http --features mcp: 172 passed
cargo clippy -p alknet-http --features mcp --all-targets: clean
cargo check -p alknet-http (no mcp): clean
glm-5.2
64696fec97