reactive-spread (module-loaded via K.load) doesn't apply CSSX classes
to DOM elements. Returns null instead of "sx-text-center". This is the
root cause of hydration stripping all styling — every rendering function
is define-bound from module load.
12 pass, 1 fail — the reactive-spread test is the blocker.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Three root causes for reactive attribute updates not propagating in WASM:
1. `context` CEK special form only searched kont provide frames, missing
`scope-push!` entries in the native scope_stacks hashtable. Unified by
adding scope_stacks fallback to step_sf_context.
2. `flush-subscribers` used bare `(sub)` call which failed to invoke
complex closures in for-each HO callbacks. Changed to `(cek-call sub nil)`.
3. Test eagerly evaluated `(deref s)` before render-to-dom saw it.
Fixed tests to use quoted expressions matching real browser boot.
WASM native: 10/10, WASM shell: 26/26.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>