Skip JIT for lambdas with closure bindings

The closure merging in jit_compile_lambda (copying globals + injecting
closure bindings into vm_env_ref) produces incorrect variable resolution
for inner functions. Symptoms: sx-parse's read-list-loop mishandles
closing parens (siblings become children), parser produces wrong ASTs.

Fix: vm_call skips JIT compilation for lambdas with non-empty closures.
These run on CEK which handles closures correctly. Top-level defines
(empty closure) are still JIT-compiled.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

shared/sx/ocaml_bridge.py

@@ -439,6 +439,7 @@ class OcamlBridge:
                         skipped += 1
                         _logger.warning("OCaml load skipped %s: %s",
                                         filepath, e)
+
                 # SSR overrides: effect is a no-op on the server (prevents
                 # reactive loops during island SSR — effects are DOM side-effects)
                 try: