build(runtime): add esbuild-based build script for dist output

- Bundle boot.ts as IIFE for main-thread script inclusion
- Bundle sw.ts as ESM with CDN imports marked external
- Inline transpiler module into SW bundle for single-file deployment
- Target ES2022, unminified for v0.1.0 readability

Author: singhjashanjot

packages/runtime/build.js

@@ -0,0 +1,29 @@
+// packages/runtime/build.js
+// Plain JS — runs with Node without compilation
+import * as esbuild from 'esbuild'
+
+// Build rawscript.js (main thread boot script — IIFE, self-executing)
+await esbuild.build({
+  entryPoints: ['src/boot.ts'],
+  bundle: true,
+  format: 'iife',
+  outfile: 'dist/rawscript.js',
+  platform: 'browser',
+  target: 'es2022',
+  minify: false, // readable for v0.1.0, minify in v0.9.0
+})
+
+// Build rawscript-sw.js (Service Worker — ESM format)
+// bundle: true so transpiler.ts is inlined, but CDN imports stay external
+await esbuild.build({
+  entryPoints: ['src/sw.ts'],
+  bundle: true,
+  format: 'esm',
+  outfile: 'dist/rawscript-sw.js',
+  platform: 'browser',
+  target: 'es2022',
+  minify: false,
+  external: ['https://unpkg.com/*'],
+})
+
+console.log('✓ rawscript built to dist/')