Adds new tile on the admin home page with system data. (#301)

* Adds new tile on the admin home page with system data. Also fixes the active users bug in the pie chart

* Fixes missing parentheses

* Updates user stats cache when signing in

* Reads active number of users from session provider

* Removes unused variable

* Small improvements

* Removes acl properties from system data websocket and performs initial push of data

* fix: remove acl fetch

---------

Co-authored-by: DecDuck <declanahofmeyr@gmail.com>

server/internal/session/memory.ts

@@ -22,6 +22,15 @@ export default function createMemorySessionHandler() {
       sessions.delete(token);
       return true;
     },
+    async getNumberActiveSessions() {
+      let activeSessions = 0;
+      for (const [_key, session] of sessions) {
+        if (session.expiresAt.getDate() > Date.now()) {
+          activeSessions += 1;
+        }
+      }
+      return activeSessions;
+    },
     async cleanupSessions() {
       const now = new Date();
       for (const [token, session] of sessions) {