Improve JWT tokens expiration

- Reduce access tokens TTL to 15 minutes
- Set refresh tokens TTL to 60 days
- Set Guardian.DB to only track refresh tokens
- Remove refresh token when logging out

Closes #710 #705 #706

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

js/src/views/Settings/Notifications.vue

@@ -385,7 +385,7 @@ export default class Notifications extends Vue {
   private async isSubscribed(): Promise<boolean> {
     if (!("serviceWorker" in navigator)) return Promise.resolve(false);
     const registration = await navigator.serviceWorker.getRegistration();
-    return (await registration?.pushManager.getSubscription()) !== null;
+    return (await registration?.pushManager.getSubscription()) != null;
   }
 
   private async deleteFeedToken(token: string): Promise<void> {