Initial commit: Star of Words Unity project

Snapshot of the existing Unity 6 language-learning word game before any
refactoring. Adds Unity .gitignore and .gitattributes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.gitattributes

@@ -0,0 +1,31 @@
+# Normalize text line endings; let Git handle CRLF on checkout
+* text=auto
+
+# Unity YAML text assets (keep as text so diffs/merges work)
+*.cs        text
+*.txt       text
+*.meta      text
+*.unity     text
+*.prefab    text
+*.asset     text
+*.mat       text
+*.anim      text
+*.controller text
+*.json      text
+*.shader    text
+*.inputactions text
+
+# Binary assets — never touch line endings
+*.png       binary
+*.jpg       binary
+*.jpeg      binary
+*.gif       binary
+*.psd       binary
+*.mp3       binary
+*.wav       binary
+*.ogg       binary
+*.ttf       binary
+*.otf       binary
+*.dll       binary
+*.aar       binary
+*.so        binary