Add missing src/lib files and fix .gitignore

- Add codec.ts, transform.ts, and types.ts to src/lib/
- Fix .gitignore to only ignore Python lib/ in root, not nested lib/ directories
- Make pointsSpent optional in AscTree type to match JSON data structure

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.gitignore

@@ -52,8 +52,8 @@ dist/
 downloads/
 eggs/
 .eggs/
-lib/
-lib64/
+/lib/
+/lib64/
 parts/
 sdist/
 var/