Improve standalone version indicator

src/build/version-loader.js

@@ -1,7 +1,8 @@
 module.exports = () => {
   if (process.env.STANDALONE) {
     const now = new Date();
-    return `export default ${JSON.stringify(`${now.getFullYear()}-${now.getMonth() + 1}-${now.getDate()}`)};`;
+    const dateString = `${now.getFullYear()}-${(now.getMonth() + 1).toString().padStart(2, '0')}-${now.getDate().toString().padStart(2, '0')}`;
+    return `export default ${JSON.stringify(`Standalone version (${dateString})`)}`;
   }
   return `export default null;`;
 };

src/p4/P4.svelte

@@ -9,7 +9,7 @@
   import Progress from './Progress.svelte';
   import Modals from './Modals.svelte';
   import {progress, theme} from './stores';
-  import {isSupported, isSafari, isStandalone} from './environment';
+  import {isSupported, isSafari} from './environment';
   import version from '../build/version-loader!';
   import {LONG_NAME, FEEDBACK_GITHUB, FEEDBACK_SCRATCH, SOURCE_CODE} from '../packager/brand';
 
@@ -109,8 +109,8 @@
   <Section accent="#ff4c4c">
     <div>
       <h1>{LONG_NAME}</h1>
-      {#if isStandalone}
-        <p><i>Standalone version ({version})</i></p>
+      {#if version}
+        <p><i>{version}</i></p>
       {/if}
       <p>{$_('p4.description1')}</p>
       <p>