Root cause: set! inside named let loop does not persist mutations
to the outer scope in the WASM kernel. tokenize-sx uses this pattern
(set! acc (append acc ...)) inside (let loop () ...) and gets empty
tokens. This makes highlight return "(<> )" for all inputs, causing
empty source code blocks on every reactive island example page.
6 failing tests document the bug at each level:
- set! in named let loop (root cause)
- tokenize-sx (empty tokens)
- highlight (empty output)
- component-source + highlight (end-to-end)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
