Move JS source from packs to entrypoints (#30037)

app/javascript/entrypoints/sign_up.js

@@ -0,0 +1,42 @@
+import './public-path';
+import axios from 'axios';
+
+import ready from '../mastodon/ready';
+
+ready(() => {
+  setInterval(() => {
+    axios.get('/api/v1/emails/check_confirmation').then((response) => {
+      if (response.data) {
+        window.location = '/start';
+      }
+    }).catch(error => {
+      console.error(error);
+    });
+  }, 5000);
+
+  document.querySelectorAll('.timer-button').forEach(button => {
+    let counter = 30;
+
+    const container = document.createElement('span');
+
+    const updateCounter = () => {
+      container.innerText = ` (${counter})`;
+    };
+
+    updateCounter();
+
+    const countdown = setInterval(() => {
+      counter--;
+
+      if (counter === 0) {
+        button.disabled = false;
+        button.removeChild(container);
+        clearInterval(countdown);
+      } else {
+        updateCounter();
+      }
+    }, 1000);
+
+    button.appendChild(container);
+  });
+});