fix(ui): show delayed busy feedback on confirm actions (#1763)

Wire ConfirmModal and BusyButton so async confirms lock immediately, show
spinner and progressive labels after duration-base, and block dismiss mid-flight.
Connect stack delete and take-down to the existing stackAction map so the dialog
is not idle until the toast.

frontend/src/components/EditorLayout/hooks/resolveStackFileKey.ts

@@ -0,0 +1,12 @@
+/**
+ * Map an overlay stack name (bare name or filename) to the key used in
+ * `stackActionMap` / stack file lists. The map is filename-keyed (e.g. `web.yml`);
+ * overlay state often holds the bare name (`web`).
+ */
+export function resolveStackFileKey(files: string[], name: string): string {
+  return (
+    files.find(
+      (f) => f === name || f.replace(/\.(yml|yaml)$/, '') === name,
+    ) ?? name
+  );
+}