Initial project setup: Rust/WASM solar system simulator with SvelteKit frontend

- Rust workspace with 4 crates: orbital-mechanics, mass-driver-core, mass-driver-wasm, mass-driver-backend
- Keplerian orbital mechanics engine with JPL elements for 14 bodies (Sun, 8 planets, Pluto, Ceres, Europa, Titan, Ganymede)
- Kepler equation solver and orbital position computation compiled to WASM
- SvelteKit frontend with Tailwind CSS, Canvas2D renderer showing animated solar system
- Orbit ellipses, planet dots with labels, Sun glow, grid, scale bar, pan/zoom controls
- Time controls (play/pause, 5 speed levels, date picker) driving live simulation
- 2D/3D view toggle (3D placeholder for Threlte integration)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/mass-driver-backend/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "mass-driver-backend"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+orbital-mechanics = { path = "../orbital-mechanics" }
+mass-driver-core = { path = "../mass-driver-core" }
+axum = "0.8"
+tokio = { version = "1", features = ["full"] }
+sqlx = { version = "0.8", features = ["runtime-tokio", "postgres"] }
+serde = { workspace = true }
+serde_json = { workspace = true }
+tower-http = { version = "0.6", features = ["cors", "compression-gzip"] }
+tracing = "0.1"
+tracing-subscriber = "0.3"

crates/mass-driver-backend/src/main.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("mass-driver backend — not yet implemented");
+}