feat(ui): implement OAuth login flow and dashboard components

* Add OAuth login handling in app and UI components
* Create new components for login and dashboard pages
* Refactor sidebar and navigation structure
* Introduce types for access entries and status responses

internal/app/status.go

@@ -90,8 +90,6 @@ func homeHandler(_ buildinfo.Info, _ *auth.AccessTracker, _ bool) http.HandlerFu
 			if serveUIAsset(w, r, requestPath) {
 				return
 			}
-			http.NotFound(w, r)
-			return
 		}
 
 		serveUIIndex(w, r)