Restructure repo so the root contains project folders. This allows
adding more Pico projects (e.g., another_project/) alongside
color_switcher/ in the same repository. All internal paths are
relative and unchanged — cd into color_switcher/ to build/flash.
Dockerized build system (Dockerfile, docker-compose, build.sh) with
Pico SDK cross-compilation. Modular CMake split into project_config,
mcu_config, and sources_config under cmake/. Component architecture
following inc/prg/cfg convention: STD_TYPES, MCU_USB, HAL_COM,
APP_CLSW, SYS_ECU. Full call chain SYS_ECU -> APP_CLSW -> HAL_COM
-> MCU_USB verified end-to-end on RP2040-Zero hardware over USB-CDC.
Includes flash.sh for automated .uf2 flashing on macOS and
devcontainer config for VS Code.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
