nx_ttt_bits_up_e2e.nx

nx_ttt_bits_up_e2e.nx -- REAL bits-up end-to-end test driving the actual nx_tictactoe game through the 5 bits-up test driver primitives. Equivalent to nishi-pages/scripts/_bits_up_check.mjs but 100% NishiLang. What this proves: the .mjs Playwright harness can be retired in favor of bits-up substrate. No JS, no Playwright, no browser engine -- the game's actual state machine + AI + render are driven through the same click-dispatch lifecycle the browser uses, with HTML emitted via fd 99 captured into a buffer, queried by the DOM primitives, asserted by the test harness DSL.