Update auth page and scripts

auth.html

@@ -24,6 +24,14 @@
     </div>
 
     <!-- Main Content Begins -->
+    <div id="top_button" class="hide_micro">
+      <a href="./">
+        <picture aria-label="Home" class="sidebar_control">
+          <source srcset="./images/nav/back.svg" type="image/svg+xml">
+          <img src="./images/nav/back-40.png" alt="Home">
+        </picture>
+      </a>
+    </div>
     <picture>
       <source srcset="./images/logo/wide_logo.svg" type="image/svg+xml">
       <source media="(max-height: 739px)" srcset="./images/logo/logo-full-200.png" type="image/png">

js/auth.js

@@ -49,6 +49,13 @@ async function checkAuth(key) {
 async function init(){ // Reads registration key from query, and calls registerKey(key)
   cmdOut("Reading authorisation code");
   const key = await getQuery("key");
+  if (key === "false") {
+    cmdOut("No valid key found")
+    cmdOut("Try clicking the link again")
+    cmdOut("or request a new activation link")
+    hideLoading()
+    return
+  }
   cmdOut("Requesting API Key from server");
   if (!await registerKey(key)) {
     cmdOut("Failed to register key")