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/db.ts

@@ -1,3 +1,5 @@
+import { DateTime } from "luxon";
+
 import prisma from "../db/database";
 import type { SessionProvider, SessionWithToken } from "./types";
 import cacheHandler from "../cache";
@@ -76,6 +78,20 @@ export default function createDBSessionHandler(): SessionProvider {
         },
       });
     },
+    async getNumberActiveSessions() {
+      return (
+        (
+          await prisma.session.groupBy({
+            by: ["userId"],
+            where: {
+              expiresAt: {
+                gt: DateTime.now().toJSDate(),
+              },
+            },
+          })
+        ).length || 0
+      );
+    },
     async findSessions(options) {
       const search: SessionWhereInput[] = [];
       if (options.userId) {