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/server/api/v1/admin/system-data/ws.get.ts

@@ -0,0 +1,36 @@
+import systemManager from "~/server/internal/system-data";
+import aclManager from "~/server/internal/acls";
+import { logger } from "~/server/internal/logging";
+
+// TODO add web socket sessions for horizontal scaling
+// Peer ID to user ID
+const socketSessions = new Map<string, string>();
+
+export default defineWebSocketHandler({
+  async open(peer) {
+    const h3 = { headers: peer.request?.headers ?? new Headers() };
+    const userId = await aclManager.getUserIdACL(h3, ["system-data:listen"]);
+    if (!userId) {
+      peer.send("unauthenticated");
+      return;
+    }
+
+    socketSessions.set(peer.id, userId);
+
+    systemManager.listen(userId, peer.id, (systemData) => {
+      peer.send(JSON.stringify(systemData));
+    });
+  },
+
+  async close(peer, _details) {
+    const userId = socketSessions.get(peer.id);
+    if (!userId) {
+      logger.info(`skipping websocket close for ${peer.id}`);
+      return;
+    }
+
+    systemManager.unlisten(userId, peer.id);
+    systemManager.unlisten("system", peer.id); // In case we were listening as 'system'
+    socketSessions.delete(peer.id);
+  },
+});