No project uses floating-point, so coprocessor_enable() was dead code. Removes rp2350_coprocessor.c/.h and all references from reset handlers and Makefiles across all 15 CBM drivers (0x01-0x0f).
- Restructure flat files into Inc/ (headers) and Src/ (sources) - Replace constants.h with rp2350.h register layer (datasheet-verified) - Add full Doxygen docstrings on all files, functions, and structs - Replace build.bat/clean.bat with cross-platform Makefile - Fix GPIO_IN offset (0x004), XOSC COUNT offset (0x10), SRAM size (520K) - Rename blink_* API to led_* (name after peripheral, not feature) - Build outputs to build/ directory - Cross-platform .vscode configs (Windows/macOS/Linux)