The Clojure stdlib namespaces (clojure.string/set/walk/edn/zip, jolt.http/
interop/shell/nrepl) were loaded cwd-relative, so the built binary couldn't
load them outside the repo. Now stdlib_embed slurps them all at build time into
a {ns -> source} map frozen in the image, and the loader falls back to it when a
namespace isn't found on disk. The artifact is self-contained — clojure.string
works from any directory.
Drops the one-off nREPL source embed (jolt.nrepl is covered by this now). The
baked-in stdlib is excluded from uberscript bundles since it's part of the
runtime. clojure.core is unchanged (Janet, auto-referred).
Test: embedded-stdlib-test requires from the embedded copy with FS roots cleared.
