Detailed Description
Top-of-splitter editor takes a C source defining extern "C" uint32_t shade(uint32_t x, uint32_t y, uint32_t w, uint32_t h). On a debounce, the source is compiled in-process via libnative (Clang + lld → .so + dlopen), and on success the resulting function is mapped across every pixel of a QImage sized to fit the preview label, using a per-activity QThreadPool with nproc-1 workers. The pixmap is rendered on top of a transparency checkerboard so the alpha channel is visible. The source code, splitter geometry, and last successful render are persisted via the Node's settings.
