Adds stm32-f4-discovery, stm32-olimex-h405, stm32-netduino-plus2, stm32-netduino2, stm32-blackpill-f401 and stm32-bluepill-f103cb, mapped to existing qemu-lcgamboa machines (netduinoplus2, olimex-stm32-h405, netduino2, stm32vldiscovery). A generic inline board renderer (no SVG) draws the Discovery/Olimex/Netduino boards from a header pin layout; the Pill variants reuse the Blue/Black Pill SVGs. Per-board onboard-LED pin and polarity via STM32_LED. One blink+serial example per board.
tsc --noEmit clean; all new FQBN pnum variants present in STM32 core 2.12.0; worker smoke tests pass for the new machines.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>