message: fix(stream-client): fix add stage placeholders are missing in UI
  fixes
diff: @@ -99,15 +99,9 @@ export class StreamDiagramComponent implements OnDestroy {
  }
  private updateAvailableSlots(streamTiles) {
  this.availableSlots = MAX_TILES - streamTiles.length;
  - // substract the slot for the add button
  + if (this.availableSlots) {
  const visiblePlaceholdersCount = this.availableSlots - 1;
  - if (
  - visiblePlaceholdersCount > 0 &&
  - this.placeholders.length !== visiblePlaceholdersCount
  - ) {
  this.placeholders = new Array(visiblePlaceholdersCount);
  - } else {
  - this.placeholders = [];
  }
  }
  }
  