test: reduce brittle assertions and test-only runtime paths (#9289)

* test: focus assertions on behavioral evidence

Prune redundant and wording-coupled checks while retaining diagnostic, parser, recovery, and cleanup coverage.

* refactor: remove test-only wrappers and duplicate checks

Exercise production operations through test fixtures, remove unused adapters, and keep managed-member uncertainty guidance under its existing owner.

* test: focus process validation on diagnostic facts

* refactor: remove test-only runtime helpers

Move semantic evidence fixture setup out of runtime and remove unused Windows settle recovery helpers while checking configured defaults independently.

* test: focus artifact diagnostics on format facts

* test: verify retained cleanup guidance delivery

tests/boundary/javascript/javascriptStaticProjectionReclamation.test.ts

@@ -387,7 +387,6 @@ it("does not discard earlier projections when live heap, not reservations, block
         if (phase === "static") heap.remainingBytes = 192 * 1024 * 1024;
       },
     );
-    expect(second.ok).toBe(false);
     if (second.ok) throw new Error("Expected live heap refusal");
     expect(second.error.error).toMatchObject({
       reportedLimits: { parent_result_budget_exhausted: true },