Improve first-run UX

- Replace LoginPage with step-by-step approach to support different login flows
- Implement login using SSO

qml/main.qml

@@ -246,6 +246,12 @@ Kirigami.ApplicationWindow {
             activeConnection: Controller.activeConnection
         }
     }
+    Connections {
+        target: LoginHelper
+        function onInitialSyncFinished() {
+            roomManager.roomList = pageStack.replace(roomListComponent);
+        }
+    }
 
     Connections {
         target: Controller
@@ -255,23 +261,13 @@ Kirigami.ApplicationWindow {
                 return;
             }
             if (Controller.accountCount === 0) {
-                pageStack.replace("qrc:/imports/NeoChat/Page/LoginPage.qml", {});
+                pageStack.replace("qrc:/imports/NeoChat/Page/WelcomePage.qml", {});
             } else {
                 roomManager.roomList = pageStack.replace(roomListComponent, {'activeConnection': Controller.activeConnection});
                 roomManager.loadInitialRoom();
             }
         }
 
-        function onConnectionAdded() {
-            if (Controller.accountCount === 1) {
-                if (Controller.busy) {
-                    pageStack.replace("qrc:/imports/NeoChat/Page/LoadingPage.qml");
-                } else {
-                    roomManager.roomList = pageStack.replace(roomListComponent);
-                }
-            }
-        }
-
         function onBusyChanged() {
             if(!Controller.busy && roomManager.roomList === null) {
                 roomManager.roomList = pageStack.replace(roomListComponent);
@@ -286,7 +282,7 @@ Kirigami.ApplicationWindow {
         function onConnectionDropped() {
             if (Controller.accountCount === 0) {
                 pageStack.clear();
-                pageStack.replace("qrc:/imports/NeoChat/Page/LoginPage.qml");
+                pageStack.replace("qrc:/imports/NeoChat/Page/WelcomePage.qml");
             }
         }