refactor: track only .cs and .md files, remove all Unity project files from git

.gitignore

@@ -1,52 +1,12 @@
-# Unity
-[Ll]ibrary/
-[Tt]emp/
-[Oo]bj/
-[Bb]uild/
-[Bb]uilds/
-[Ll]ogs/
-[Uu]ser[Ss]ettings/
-[Mm]emoryCaptures/
-[Cc]rashReportLogs/
+# Ignore all files
+*
 
-# Visual Studio
-.vs/
-*.csproj
-*.unityproj
-*.sln
-*.suo
-*.user
-*.userosscache
-*.sln.docstates
-*.userprefs
+# Unignore directories (needed so git can look inside)
+!*/
 
-# JetBrains Rider
-.idea/
-*.sln.iml
+# Only track .cs and .md files
+!*.cs
+!*.md
 
-# macOS
-.DS_Store
-*.swp
-*.lock
-
-# Windows
-Thumbs.db
-
-# VS Code
-.vscode/
-
-# Claude Code
-.claude/
-
-# Git LFS
-*.fbx
-*.FBX
-*.tga
-*.tif
-*.tiff
-*.psd
-*.wav
-*.mp3
-*.mp4
-*.avi
-*.mov
+# And the gitignore itself
+!.gitignore