The BoardKind type and the QEMU backend already supported
raspberry-pi-4 (Cortex-A72) and raspberry-pi-5 (Cortex-A76) by reusing
the Pi 3 arm64 image set, but the frontend had no way to actually
select either: the board picker, the canvas renderer, the serial
monitor, the oscilloscope channel list, and the editor toolbar all
hard-coded "raspberry-pi-3" as the only Pi entry. ComponentRegistry
even registered Pi 4 / Pi 5 metadata pointing at the velxio-raspberry-pi-3
custom-element tag — a placeholder that meant both boards rendered as
a Pi 3 in the picker thumbnail and on the canvas.
Add dedicated boards top-to-bottom:
* `RaspberryPi4Element.ts` / `RaspberryPi5Element.ts` — Velxio-style
schematic SVG (authored from scratch, not traced). Pi 4 is the
green PCB with BCM2711 SoC, 4× USB-A, USB-C power, dual µHDMI;
Pi 5 is the darker green PCB with BCM2712 + RP1 southbridge,
2.5 GbE, USB-C 5V/5A, PCIe FFC connector, dedicated power
button. Both carry a small "velxio" mark in the corner.
* `pi40PinHeader.ts` — shared `buildPi40PinHeader()` helper that
returns the 40-pin BCM layout. Every Pi from the 1B+ onwards
uses the same physical pin positions and same BCM GPIO
assignment, so Pi 3 / Pi 4 / Pi 5 elements all consume this
helper and example wires drawn against one model transfer to
the others without re-routing.
* React wrappers `RaspberryPi4.tsx` / `RaspberryPi5.tsx` render the
custom elements at absolute positions (mirrors how
RaspberryPi3.tsx handles the Pi 3 illustration).
* Wire-up across the editor surface:
- BoardOnCanvas: BOARD_SIZE entry + switch case.
- BoardPickerModal: description, icon, kinds list.
- ComponentPickerModal: thumbnails now instantiate the dedicated
custom element (was velxio-raspberry-pi-3 fallback).
- SerialMonitor / EditorToolbar: pill labels, icons, colours.
- Oscilloscope: GPIO channel list (28 BCM pins).
- SimulatorCanvas: remote-boards filter for run/stop sync.
- SPICE boardPinGroups: same 5V / 3V3 / GND as Pi 3.
- boardPinToNumber: accepts physical pin numbers ("1"-"40"),
BCM names ("GPIO14") and power labels for any Pi 3/4/5 id.
- ComponentRegistry: dedicated tagNames + per-board thumbnails
(green for Pi 4, darker green for Pi 5).
* EditorToolbar's Pi 3 special cases (Linux/Python compile path,
Run/Stop routing) now use `isPiBoardKind()` so Pi 4 and Pi 5
inherit the same behaviour automatically, and any future Pi
family member (Zero / 1 / 2) lands in the right code paths the
moment its backend boots.
QEMU backend was already wired (qemu_manager.py:71/82 + manifest entry
'raspberry-pi-3-virt' shared across arm64 Pis), so this commit makes
both boards selectable end-to-end without any backend follow-up.