simulator-inputs: move dynamic import to top level so heavy module
initialization happens during file load (no timeout) instead of inside
the test body.
llws-simulator: make iteration count injectable via constructor
(default 50_000 for production, tests pass 1_000). Cuts test suite
from ~4s per test to <150ms for all 21 tests combined.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>