Room list: assign room to section when section is created (#33240)

* feat(rls): return section tag when created

* feat(vm): assign section tag to room when section created

* test: update exisiting tests

* test(e2e): check that room is in section

apps/web/src/stores/room-list-v3/RoomListStoreV3.ts

@@ -491,10 +491,11 @@ export class RoomListStoreV3Class extends AsyncStoreWithClient<EmptyObject> {
      * Create a new section.
      * Emits {@link SECTION_CREATED_EVENT} if the section was successfully created.
      */
-    public async createSection(): Promise<void> {
+    public async createSection(): Promise<string | undefined> {
         const tag = await createSection();
         if (!tag) return;
         this.emit(SECTION_CREATED_EVENT, tag);
+        return tag;
     }
 
     /**

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

@@ -400,8 +400,12 @@ export class RoomListItemViewModel
         echoChamber.notificationVolume = elementNotifState;
     };
 
-    public onCreateSection = (): void => {
-        RoomListStoreV3.instance.createSection();
+    public onCreateSection = async (): Promise<void> => {
+        const newTag = await RoomListStoreV3.instance.createSection();
+        // Add the room to the section
+        if (newTag) {
+            tagRoom(this.props.room, newTag);
+        }
     };
 
     public onToggleSection = (tag: string): void => {