feat(runtime): add main-thread boot script with SW registration

- Register rawscript-sw.js as a module-type Service Worker
- Auto-reload page on first SW activation for fetch interception
- Guard registration behind serviceWorker feature detection
- Mark SW path as configurable for v0.9.0 (data-sw-path attr)

Author: singhjashanjot

packages/runtime/src/boot.ts

@@ -0,0 +1,14 @@
+// TODO v0.9.0: make this configurable via data-sw-path attribute
+const SW_PATH = '/rawscript-sw.js'
+
+if ('serviceWorker' in navigator) {
+  navigator.serviceWorker.register(SW_PATH, { type: 'module' }).then((reg) => {
+    if (reg.installing) {
+      reg.installing.addEventListener('statechange', (e) => {
+        if ((e.target as ServiceWorker).state === 'activated') {
+          location.reload()
+        }
+      })
+    }
+  })
+}