v0.8.5 - Cycle-Accurate CPU/PPU Synchronization Key Features: - Cycle-accurate CPU/PPU synchronization (M11 S1 & S2) - CpuBus trait with on_cpu_cycle() callback - VBlank timing tests pass with ±0 cycle accuracy - 520+ tests passing, 100% Blargg pass rate Technical Highlights: - PPU stepped 3 dots BEFORE each CPU memory access - cpu.tick() for cycle-by-cycle execution - NMI handling via callback system