feat: Scaffold repo and migrate simulation/validation tools.

[nedseb]

Context

The simulation and validation tools currently live in micropython-steami-tutorials but are development tools that serve a different purpose than tutorials. They are being moved to this dedicated repo as part of the tutorials restructuring.

What to migrate

Source (tutorials)	Destination (this repo)
sim/sim_backend.py	sim/sim_backend.py
validate.py	validate.py
tools/board_validate.py	board_validate.py
generate_report.py	generate_report.py
docs/mockups/ (SVG + PNG + diff + README)	docs/mockups/

Tasks

Scaffolding

• Add Makefile (same pattern as micropython-steami-lib)
• Add package.json (husky, commitlint, lint-staged)
• Add commitlint.config.js
• Add .husky/ hooks
• Add .gitignore
• Add CONTRIBUTING.md
• Add CI workflows (lint, tests)

Migration

• Move sim_backend.py
• Move validate.py and adapt paths
• Move board_validate.py and adapt paths
• Move generate_report.py and adapt paths
• Move docs/mockups/ (SVG references + generated assets)
• Add Python dependencies (Pillow, cairosvg, scikit-image)
• Configure dependency on micropython-steami-lib (for steami_screen imports)
• Verify python validate.py produces same SSIM scores as before

Related

• feat: Migrate steami_screen library from tutorials repo. micropython-steami-lib#266 — steami_screen migration
• steamicc/micropython-steami-tutorials — cleanup after migration