feat: add login expiry check

web/app/src/AuthCheck.svelte

@@ -1,9 +1,10 @@
 <script>
     import { token } from "./stores.js";
+    import { isTokenExpired } from "./login-check.js";
 
     let loggedIn = false;
     token.subscribe((value) => {
-        loggedIn = value !== "";
+        loggedIn = !isTokenExpired(value);
     });
 </script>
 

web/app/src/AuthRequired.svelte

@@ -2,10 +2,11 @@
     import { token } from "./stores.js";
     import { navigate } from "svelte-routing";
     import { onMount } from "svelte";
+    import { isTokenExpired } from "./login-check.js";
 
     let loggedIn = false;
     token.subscribe((value) => {
-        loggedIn = value !== "";
+        loggedIn = !isTokenExpired(value);
     });
 
     onMount(() => {

web/app/src/Navbar.svelte

@@ -1,12 +1,13 @@
 <script>
     import { Link } from "svelte-routing";
     import { token } from "./stores.js";
+    import { isTokenExpired } from "./login-check.js";
 
     let menu_shown = false;
 
     let loggedIn = false;
     token.subscribe((value) => {
-        loggedIn = value !== "";
+        loggedIn = !isTokenExpired(value);
     });
 
     const toggleMenu = () => {

web/app/src/login-check.js

@@ -0,0 +1,8 @@
+const isTokenExpired = (token) => {
+    if (token === "") return true;
+    
+    const expiry = (JSON.parse(atob(token.split('.')[1]))).exp;
+    return (Math.floor((new Date).getTime() / 1000)) >= expiry;
+}
+
+export { isTokenExpired }