feat: Migrate hardware validation (board_validate.py).

[nedseb]

Description

Move the hardware validation tool from micropython-steami-tutorials.

Source

micropython-steami-tutorials/tools/board_validate.py (427 lines)

Tasks

• Copy board_validate.py
• Adapt paths for new repo structure
• Verify python board_validate.py works with a connected STeaMi board
• Add CLI documentation in README

Features

• Extracts draw() body from screenshot.py using inspect
• Injects into MicroPython template for board execution
• Runs on board via mpremote
• Dumps GS4_HMSB framebuffer as hex
• Decodes to PIL Image
• Compares: board vs sim, board vs SVG ref
• Generates diff images

Dependencies

• feat: Migrate Pillow simulator (sim_backend). #3 — SimBackend must be migrated first
• Requires physical STeaMi board + mpremote

Parent

• feat: Scaffold repo and migrate simulation/validation tools. #1 — Migration umbrella issue