- Add POST /api/sim/run-n-player endpoint accepting 2-4 deck IDs for N-player batch simulations using the existing engine.run_n() method - Add _run_sim_thread_n_player tracking per-seat wins and stats - Create SimulatorPage.tsx with 4 deck selection slots, config row, progress bar, results table, CSS bar chart, and per-game logs - Add simulator types in frontend/src/types/simulator.ts - Add /simulator route and nav bar to App.tsx Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>