docs: rank the destructive generator as item 0

It was written up in 4.7 but never made the work order, which is exactly how it
stayed dangerous in the first place.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

examples/inter-app-api-showcase/apps/admin/.env.test.example

@@ -0,0 +1,3 @@
+WRNEXUS_PUBLIC_ORIGIN=http://localhost:3000
+DATABASE_URL=file:./test.db
+AUTH_SECRET=test-only-secret-replace-outside-tests