chore: import upstream snapshot with attribution

client/static/python-input-sw.js

@@ -0,0 +1,23 @@
+self.addEventListener('install', function() {
+  self.skipWaiting();
+});
+
+self.addEventListener('activate', function() {
+  self.clients.claim();
+})
+
+let resolver;
+
+self.onmessage = function(event) {
+  if (resolver) resolver(event.data);
+}
+
+self.addEventListener('fetch', (event) => {
+  const url = new URL(event.request.url);
+  if (url.pathname === '/python/intercept-input/') {
+    const response = new Promise((resolve) => {
+      resolver = (data) => resolve(new Response(data));
+    });
+    event.respondWith(response);
+  }
+});