Mirrors #26550 (Provider.toPublicInfo): internal runtime objects may
legitimately carry function/symbol/bigint/undefined values, but the
HTTP API contract is JSON-safe data matching the typed schema.
Plugin `config:` hooks are documented to mutate cfg in place
(registering agents/providers); that contract is preserved. The
projection happens in ConfigHttpApi.get only, so internal consumers
keep raw cfg and HTTP clients see a clean response.
Active reproducer asserts the actual product invariant — GET /config
returns a JSON-safe body even when a plugin attached a function to
cfg. Three trigger-output reproducers stay skipped: per-hook design
needed because the documented mutation contract makes a blanket
clone unsafe and `tool.parameters` is a live Effect Schema with
function-valued own keys that recursive in-place scrub would corrupt.
6833070a57