chore: initialize frontend repo with teaching terminology updates

Add the current frontend codebase with a baseline .gitignore and update piano-specific UI terms to teaching-oriented terms for the current product context.

Made-with: Cursor

container/setup.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+set -x
+
+if [[ ! -d "/home/nginx" ]]; then
+  mkdir /home/nginx
+  chown nginx:nginx /home/nginx/
+fi
+