Build a true 3D HTML5 space shooter in one single HTML file.
Tech: use Three.js via CDN/importmap, with PerspectiveCamera and real 3D meshes.
Theme: deep nebula background, emissive laser effects, clean futuristic HUD.
Camera: chase camera slightly behind and above player ship.
Core loop: move ship, shoot enemy waves, survive escalating pressure.
Weapons: burst fire with short cooldown; temporary shield on Shift.
Enemies: 3 types with clear telegraphed attacks.
UI: score, lives, shield cooldown, wave indicator, start/game-over overlays.
Controls: Arrow keys to move, Space to shoot, Shift for shield.