chore: ignore playground .desktop runtime artifacts

Co-authored-by: Cursor <[email protected]>

Author: dxlliv

.gitignore

@@ -10,6 +10,7 @@ dist
 playground/.nuxt
 playground/.output
 playground/dist
+playground/.desktop
 
 # Local static preview (copy for serve; CI uses playground/.output/public)
 preview-root/