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

cdn/upload_assets.sh

@@ -0,0 +1,12 @@
+#!/bin/sh
+set -x
+
+CONFIG=${1:-./.local_upyun_pass}
+
+SERVER=${2}
+
+for FILE in $(ls -1 ../dist/assets)
+do
+    upyun_tool --upload /assets/$FILE ../dist/assets/$FILE --config $CONFIG --server $SERVER
+done
+