SB-005-VMU_INTEGRATION.md (P1, 314 lines)

• VMU display and input integration via SPECTRE Spec 1
• VMU hardware: 48x32 monochrome LCD, 192-byte framebuffer, 2 buttons + D-pad, 128KB flash
• Architecture: VMU Manager → Device Enumerator, VMU Renderer → Frame Buffer → KOS VMU APIs
• Data structures: d3tui_vmu_addr_t (port/slot), d3tui_vmu_info_t, d3tui_vmu_display_t, d3tui_vmu_t, d3tui_vmu_manager_t
• API: create/destroy, detect, get_info, enable/set_contrast/clear, render_char/text/bitmap, attach_terminal, update/update_all
• Uses SPECTRE Spec 1 functions: sh_vmu_at, sh_vmu_first, sh_vmu_count, sh_vmu_each, sh_vmu_clear, sh_vmu_blit, sh_vmu_print, sh_vmu_present
• Three terminal modes: Mirror (subset of main), Independent (own instance), Debug (FPS/memory)
• Built-in 6x8 pixel monochrome font for VMU (96 chars: 32-127)
• Performance: Maple bus ~1.5Mbps, ~1ms latency per transaction