v0.26.1

Apache NuttX RTOS backend — feature = "nuttx" runs mirui against /dev/fbN framebuffer + /dev/inputN touchscreen + optional /dev/kbdN keyboard, verified on ESP32-C3 (ST7735 SPI LCD) and qemu virtio-gpu. The framebuffer pointer comes straight from FBIOGET_PLANEINFO with no mmap. PointerState and the DPI scale heuristic are shared with the Linux backends via a small cross-platform refactor.

Added

• feature = "nuttx" — opt-in NuttX backend on libc 0.2, gated on target_os = "nuttx". NuttxFbSurface::open(NuttxConfig) wires the framebuffer, touchscreen, optional keyboard, and a SIGTERM/SIGINT quit handler.
  • Framebuffer via FBIOGET_VIDEOINFO / FBIOGET_PLANEINFO (direct pointer, RGB565 / RGB888 / BGRA8888 / RGBA8888).
  • NuttxConfig::use_paninfo controls per-frame FBIOPAN_DISPLAY; None auto-detects (virtio-gpu / DRM-style fb pan, SPI LCD doesn't).
  • Multi-touch via the shared PointerState; optional /dev/kbdN keyboard mapping X11 keysyms.
  • Diagnostics go through NuttX syslog(3) (libstd's stderr blocks on USB-Serial/JTAG consoles).
  • NuttxConfig: fb_path, touch_path, keyboard_path, display_index, overscan_inset_percent, scale, use_paninfo.
• NuttX target CI gate — compiles the nuttx feature for riscv32imac-unknown-nuttx-elf.

Fixed

• framebuffer() view extents are validated against fblen at open, so an overscan offset can't build an out-of-bounds slice.
• flush clamps rect endpoints to display bounds instead of only the width/height.

Changed

• PointerState + InputAxis moved to a cross-platform surface/input_state.rs (and the DPI heuristic to surface/scale.rs) so the NuttX backend reuses them verbatim.