Move wasm package under packages

site/decodal-site/scripts/prepare-wasm-package.mjs

@@ -0,0 +1,53 @@
+import { writeFileSync } from 'node:fs';
+import { resolve } from 'node:path';
+
+const packageDir = resolve(import.meta.dirname, '../../../packages/decodal-wasm');
+
+writeFileSync(
+  resolve(packageDir, '.gitignore'),
+  '# wasm-pack output is committed for the browser runtime package.\n',
+);
+
+writeFileSync(
+  resolve(packageDir, 'README.md'),
+  `# decodal-wasm
+
+WebAssembly runtime package for Decodal.
+
+This package exposes the Decodal evaluator to browsers and other JavaScript runtimes that can load WebAssembly modules.
+It is generated from the Rust crate in \`crates/decodal-wasm\` with \`wasm-pack\` and is used by the official playground.
+
+Use \`decodal-codemirror\` separately when you need CodeMirror 6 language support.
+
+## Install
+
+\`\`\`sh
+npm install decodal-wasm
+\`\`\`
+
+JSR:
+
+\`\`\`sh
+deno add jsr:@hare/decodal-wasm
+\`\`\`
+
+## Usage
+
+\`\`\`js
+import init, { evaluateProject } from 'decodal-wasm';
+
+await init();
+
+const result = evaluateProject(JSON.stringify({
+  entry: 'main.dcdl',
+  files: {
+    'main.dcdl': 'Server = { port = Int default 8080; };',
+  },
+}));
+
+console.log(JSON.parse(result));
+\`\`\`
+
+The exported functions return JSON strings so callers can handle diagnostics and successful results without depending on Rust data structures.
+`,
+);