Preserve RNG state in eval context

app.py

@@ -239,9 +239,11 @@ def _get_eval_context(seed: int) -> dict:
         cached = _eval_context.get(seed)
         if cached is not None:
             return cached
+    rng_state = random.getstate()
     random.seed(seed)
     forest = Tree.generate(10)
     inp = Input.generate(forest, 256, 16)
+    random.setstate(rng_state)
     mem0 = build_mem_image(forest, inp)
     ref_mem = None
     for ref_mem in reference_kernel2(list(mem0)):