VM frame merging bug: call_closure_reuse now saves caller continuations
on a reuse_stack instead of merging frames. resume_vm restores them in
innermost-first order. Fixes frame count corruption when nested closures
suspend via OP_PERFORM. Zero test regressions (3924/3924).
Island hydration: hydrate-island now looks up components from (global-env)
instead of render-env, triggering the symbol resolve hook. Added JS-level
preload-island-defs that scans DOM for data-sx-island and loads definitions
from the content-addressed manifest BEFORE hydration — avoids K.load
reentrancy when the resolve hook fires inside env_get.
loadDefinitionByHash: fixed isMultiDefine check — defcomp/defisland bodies
containing nested (define ...) forms no longer suppress name insertion.
Added K.load return value checking for silent error string returns.
sx_browser.ml: resolve hook falls back to global_env.bindings when
_vm_globals miss (sync gap). Snapshot reuse_stack alongside pending_cek.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>