fix(game-of-life): repair 3D Life module imports

[miuchan]

Motivation

• The 3D Life demo failed to start in some environments because browser module specifiers for Three.js and its examples were not resolving consistently from remote URLs, preventing the simulation from loading.

Description

• Added an importmap to public/demo/game-of-life/3d-life/index.html that maps three and three/addons/ to stable unpkg module URLs.
• Updated public/demo/game-of-life/3d-life/life3d.js to import three and three/addons/controls/OrbitControls.js via the import map aliases so the browser can resolve modules correctly.

Testing

• Ran node --check public/demo/game-of-life/3d-life/life3d.js, which completed successfully and found no syntax errors.
• Attempted an automated Playwright screenshot to validate runtime loading, but the headless Chromium process crashed with a SIGSEGV in this environment so the visual verification could not be completed.

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Codex Task