Implement tiled multiplayer city simulation and scaling stages

tools/rust.mjs

@@ -0,0 +1,14 @@
+import { existsSync } from 'node:fs';
+import { resolve, delimiter } from 'node:path';
+import { spawn } from 'node:child_process';
+const local = resolve('.tools/cargo');
+const executable = resolve(local,'bin',process.platform === 'win32' ? 'cargo.exe' : 'cargo');
+const env = {...process.env};
+if (existsSync(executable)) {
+  env.CARGO_HOME = local; env.RUSTUP_HOME = resolve('.tools/rustup');
+  const pathKey=Object.keys(env).find(key=>key.toLowerCase()==='path') || 'PATH';
+  env[pathKey] = `${resolve(local,'bin')}${delimiter}${env[pathKey] || ''}`;
+}
+const child = spawn(existsSync(executable) ? executable : 'cargo',process.argv.slice(2),{stdio:'inherit',env});
+child.on('error',error=>{console.error(`Rust toolchain is required: ${error.message}`);process.exitCode=1;});
+child.on('exit',code=>{process.exitCode=code ?? 1;});