diff --git a/plugin-designs/research-dashboard/src/composables/useSelectionBus.js b/plugin-designs/research-dashboard/src/composables/useSelectionBus.js
deleted file mode 100644
index 5369f92ae..000000000
--- a/plugin-designs/research-dashboard/src/composables/useSelectionBus.js
+++ /dev/null
@@ -1,18 +0,0 @@
-/**
- * useSelectionBus.js — RE-EXPORT SHIM (dashboard-kit landing 1).
- *
- * The bus now lives at library/composables/useSelectionBus.js. This file exists so the move and
- * its consumers do not have to land in the same commit: every importer keeps working unchanged for
- * one cycle, and the ones that still point here are migrated in the next landing, after which this
- * file is deleted.
- *
- * WHY A SHIM AND NOT A SIMULTANEOUS REWRITE. The extraction's governing constraint is that Big
- * Picture must not change, and the only way to prove that for nine landings in a row is to make
- * each one small enough to verify on its own. A landing that moves a file AND rewrites every
- * import is two changes whose failures look identical from the outside.
- *
- * NOT A SECOND COPY. It re-exports; it does not duplicate. A copy would drift silently and both
- * halves would keep passing their gates — which is the exact failure check:no-cross-plugin-imports
- * and check:shared-reached exist to stop.
- */
-export { createSelectionBus, deriveHierarchy } from '@map/composables/useSelectionBus.js'