fixing some errors

frontend/assets/js/app.js

@@ -69,6 +69,12 @@ async function performLogin(authToken) {
             if (data.role === 'admin') document.getElementById('settingsBtn').classList.remove('d-none');
             document.getElementById('loginOverlay').style.display = 'none';
             window.history.replaceState({}, '', '/');
+            // Init canvas if not already
+            if (!canvas) {
+                canvas = document.getElementById('networkCanvas');
+                ctx = canvas.getContext('2d');
+                resizeCanvas();
+            }
             loadTeams().then(() => loadEvents());
             loadNetworkData();
         } else {