allow viewing space timelines

Fixes #139

lib/helpers/extensions/room_destinations.dart

@@ -4,20 +4,28 @@ import "package:navigation_rail_m3e/navigation_rail_m3e.dart";
 import "package:nexus/models/room.dart";
 import "package:nexus/widgets/avatar_or_hash.dart";
 
+extension RoomDestination on Room {
+  NavigationRailM3EDestination toDestination({
+    required bool isDm,
+    String? label,
+    Widget? icon,
+  }) => NavigationRailM3EDestination(
+    label: label ?? metadata?.name ?? "Unnamed Room",
+    badgeCount: switch (metadata?.unreadNotifications) {
+      0 || null => metadata?.unreadMessages == 0 ? null : 0,
+      int unread => unread,
+    },
+    icon:
+        icon ??
+        AvatarOrHash(
+          metadata?.avatar,
+          metadata?.name ?? "Unnamed Room",
+          fallback: isDm ? null : const Icon(Icons.numbers),
+        ),
+  );
+}
+
 extension RoomDestinations on IList<Room> {
   List<NavigationRailM3EDestination> toDestinations({required bool isDm}) =>
-      map(
-        (room) => NavigationRailM3EDestination(
-          label: room.metadata?.name ?? "Unnamed Room",
-          badgeCount: switch (room.metadata?.unreadNotifications) {
-            0 || null => room.metadata?.unreadMessages == 0 ? null : 0,
-            int unread => unread,
-          },
-          icon: AvatarOrHash(
-            room.metadata?.avatar,
-            room.metadata?.name ?? "Unnamed Room",
-            fallback: isDm ? null : const Icon(Icons.numbers),
-          ),
-        ),
-      ).toList();
+      map((room) => room.toDestination(isDm: isDm)).toList();
 }