Two paren bugs in home-stepper.sx caused the home page to render blank:
1. Line 222 had one extra ) that prematurely closed the letrec bindings
list — rebuild-preview and do-back became body expressions instead
of bindings, making them undefined in scope.
2. Lines 241-308 were outside the let/letrec scope entirely — the outer
let closed at line 240, so freeze-scope, cookie restore, source
parsing, and the entire div rendering tree had no access to signals
or letrec functions.
Also hardens defisland to wrap multi-expression bodies in (begin ...),
matching the Python-side fix from 9f0c541. Both spec/evaluator.sx and
the OCaml transpiled sx_ref.ml are updated.
Adds SX Tools essay under Applications — the revised plan for structural
tree reading/editing tools for .sx files, motivated by this exact bug.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
giles
c18f46278f