Room list: improve custom sections in Spaces (#33523)

* feat: display empty custom sections in the space where they were created

* test: update tests

* fix: room can't be drag in to a section if a section is created before

* fix: re-render issue when section is created

apps/web/src/viewmodels/room-list/RoomListViewModel.ts

@@ -645,6 +645,10 @@ export class RoomListViewModel
     };
 
     public onSectionCreated = (tag: string): void => {
+        // Refresh roomsResult so the new section lands in the same snapshot as the scroll-to.
+        const filterKeys = this.activeFilter !== undefined ? [this.activeFilter] : undefined;
+        this.roomsResult = RoomListStoreV3.instance.getSortedRoomsInActiveSpace(filterKeys);
+        this.updateRoomsMap(this.roomsResult);
         this.updateRoomListData(false, null, tag);
         this.showToast("section_created");
     };
@@ -694,9 +698,11 @@ function computeSections(
     const customSections = getCustomSectionData();
 
     const sections = roomsResult.sections
-        // Only include sections that have rooms or are custom sections (which may be empty but should still be shown)
+        // Only include sections that have rooms, or custom sections that were created in the current space.
         .filter(
-            (section) => section.rooms.length > 0 || (isCustomSectionTag(section.tag) && customSections[section.tag]),
+            (section) =>
+                section.rooms.length > 0 ||
+                (isCustomSectionTag(section.tag) && customSections[section.tag]?.spaceId === roomsResult.spaceId),
         )
         // Remove roomIds for sections that are currently collapsed according to their section header view model
         .map((section) => ({