v0.0.193

Added

• <HttpServer> — verified HTTP request handling, served by vera serve (#305). A server program defines a total, contract-checked handler — public fn handle(@Request -> @Response) effects(<HttpServer>) — and vera serve prog.vera [--port N] hosts the accept loop: the loop lives in the host, so handlers need no Diverge, are termination-checked like any function, and every contract on the handler (or its helpers) is an ordinary Tier-1/Tier-3 obligation (the new examples/http_server.vera proves a status-range postcondition at Tier 1). HttpServer is a built-in marker effect (no operations; spec §7.7.5); Request (method, path, headers, body) and Response (status, headers, body) are prelude ADTs injected when referenced (headers are Map<String, String>; user definitions shadow). Per-request isolation: each request runs on a fresh module instance (fresh execute() — instantiation measured at ~0.02 ms in the Stage-0 spike), so State<T> cannot leak between requests (pinned by test). A runtime contract violation (or any trap) inside a handler answers 500 with the trap diagnostic as a JSON body (trap_kind, message, frames — the vera run --json envelope shape); the connection is always answered. Host marshalling is layout-driven: CompileResult.adt_layouts exports the constructor layouts this compilation computed, build_request_adt shadow-roots every intermediate allocation (#570/#692 discipline), decode_response_adt reads the returned ADT, and both fail loudly on an unexpected layout shape; a new InstanceCaller adapts a (Store, Instance) pair to the caller protocol the heap helpers already use. Handler IO.print goes to the server console; request handling is sequential in v1 (concurrency: #406); native-only (the browser runtime does not serve HTTP — documented divergence, spec §12.9.3). Also fixed en route: Pass-1 function signatures that reference prelude ADTs in params/return were computed before prelude registration and recorded unsupported in fn_param_types — a post-injection pass now re-registers exactly those. New: tests/conformance/ch09_http_server.vera (level verify — needs no network, unlike ch09_http), examples/http_server.vera, spec §9.5.6, and a TOOLCHAIN.md serve recipe.