fix(launchpad): Select root for initial breadcrumb (#103236)

Resolves EME-587

Author: chromy

static/app/views/preprod/components/visualizations/appSizeTreemap.tsx

@@ -204,6 +204,12 @@ export function AppSizeTreemap(props: AppSizeTreemapProps) {
       height: `calc(100% - 22px)`,
       width: '100%',
       top: '22px',
+      // Very mysteriously this controls the initial breadcrumbs:
+      // https://github.com/apache/echarts/blob/6f305b497adc47fa2987a450d892d09741342c56/src/chart/treemap/TreemapView.ts#L665
+      // If truthy the root is selected else the 'middle' node is selected.
+      // It has to be set to large number to avoid problems caused by
+      // leafDepth's main use - controlling how many layers to render.
+      leafDepth: 100000,
       breadcrumb: {
         show: true,
         left: '0',