createApiProxy moves from dsh-host-runtime into dsh-host-apiproxy (the
dependency direction already pointed this way); the package now
default-exports ApiProxyService (config {provider, model}, provides
ctx.apiProxy) while staying transport-agnostic — it registers no routes.
Runtime keeps bootHost/startHost for the headless path with its import
re-anchored, and drops the mountWebPlugins roster mounting helper.
3cad7f6957