nx_test_driver_e2e.nx

nx_test_driver_e2e.nx -- end-to-end smoke for the bits-up test driver. Composes all 5 primitives (nx_dom_query + nx_dom_click + nx_url_params + nx_test_harness + nx_game_harness) against an inline "fake game" that emits the same HTML shape as nx_tictactoe_render.nx. Why a fake game instead of importing nx_tictactoe.nx directly: the real game's render imports nx_syscalls.nx (RV64); the harness imports nx_syscalls_x86_64.nx; combining them creates duplicate-symbol errors. Cross-arch cleanup of the substrate's syscall layer is the queued follow-up; this smoke validates the *primitives* end-to-end and produces the same test-output format the .mjs harnesses do, proving the architecture works. The fake game models a 3x3 grid like tic-tac-toe. State is 9 cells + last-move indicator. Render emits buttons with class="cell" and data-cell-idx="N". Action 1 with arg0=N places an X at cell N.