Rewrite SpaceWar in Rust + WebAssembly for browser play

[Copilot]

The original Java/Swing desktop game is inaccessible on the web. This adds a complete Rust + WebAssembly port, deployable as a static site (GitHub Pages), preserving all original gameplay mechanics.

What's new

spacewar-wasm/src/lib.rs — Rust game engine

• SpaceWarGame struct exported via wasm-bindgen; three public entry points: tick(ts), on_key_down(key, code), on_mouse_move(x, y)
• Full game state machine: Menu → Playing → GameOver
• All original mechanics faithfully ported: AABB collision detection, score-based ship level progression (every 250 pts, 8 tiers), 3-bullet spread at high levels, enemy AI spawning/shooting with difficulty scaling
• Movement uses Δt normalization (same physics feel as the original Java thread-sleep timings)
• Canvas 2D rendering via web-sys — draw_image / draw_image_scaled; all 100 sprites accessed via a flat indexed array matching the JS manifest

// JS drives the loop; Rust owns all state and renders to the canvas
pub fn tick(&mut self, timestamp: f64) { /* Δt update + render */ }
pub fn on_key_down(&mut self, key: String, key_code: u32) { /* ship select / fire */ }
pub fn on_mouse_move(&mut self, x: f64, y: f64) { /* ship follows cursor */ }

spacewar-wasm/www/index.html — thin JS shell

• Loads all 100 sprites in parallel with a progress bar, then hands the HTMLImageElement[] array to Rust
• requestAnimationFrame loop calls game.tick(ts); keyboard/mouse/touch events forwarded to Rust
• Canvas coordinates scaled from CSS pixels back to the logical 1300×720 game space, so the layout is responsive

spacewar-wasm/www/assets/ — sprite tree

• 113 PNGs copied from src/lassa/net/imagenes/ and organized without path spaces (removes the "nave 1/" naming issue from the Java classpath)

.github/workflows/deploy-pages.yml — CI/CD

• Builds WASM with wasm-pack on every push to master touching spacewar-wasm/**, uploads www/ as a Pages artifact, and deploys

Updated README.md

• Documents both versions, play controls, architecture diagram, and local build steps (wasm-pack build --target web --out-dir www/pkg)

Why Rust + WASM over a JS framework

Rust compiles to a 54 KB WASM binary with direct Canvas 2D access via web-sys — no framework overhead, no GC, and a stronger portfolio signal than a React/Next.js port.