Add: backend testing script for new states

docs/RANDOM_BACKEND_TESTING.md

@@ -18,6 +18,13 @@ Supporting checks:
 - `GET /v1/health`
 - `GET /v1/state` (periodic sampling)
 
+Animation traffic now targets row-based sprite names plus compatibility aliases:
+
+- semantic names: `idle`, `happy`, `love`, `excited`, `celebrate`, `sleepy`, `snoring`,
+  `working`, `angry`, `surprised`, `shy`, `dragging`
+- compatibility aliases: `active`, `success`, `error`
+- one intentional unknown name is still included to keep invalid animation-path coverage
+
 ## Prerequisites
 
 - Frontend runtime is already running (`sprimo-app` or `sprimo-tauri`).