Add playable Snake game at /snake/

[assertion]

Summary

• Adds a self-contained Snake game (canvas + CSS/JS) at /snake/ with arrow/WASD controls, swipe + on-screen pad, score/best, and restart on game over.
• Links Snake in the site nav; uses a lightweight game layout (no ads/comments) and optional extra_css / extra_js page front matter.
• Moss/ink UI fits the existing Palatino blog look. Movement starts on the first steer so the snake does not race into a wall before input.

Play locally

jekyll serve --config _config.yml,_config_local.yml --host 0.0.0.0 --port 4000

Open http://localhost:4000/snake/.

Test plan

• Load /snake/ — Play overlay, score HUD, Restart, direction pad
• First steer starts movement; snake grows on food; wall/self collision ends the game
• After game over, Play again / Restart start a new run; best score persists
• On-screen pad steers; nav “Snake” link present
• Automated Playwright playtest (eat food, pad, wall death, restart)

Snake mid-game score 1
snake_gameplay_demo.mp4

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