Remove Claude Code artifacts from repository

- Remove CLAUDE.md and .claude/ from git tracking
- Add Claude Code artifacts to .gitignore
- Keep repository clean of development tooling files

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

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

Author: jeongyoonlee

.claude/commands/fix-github-issue.md

@@ -20,4 +20,8 @@ _build/
 *.prof
 .venv/
 .python-version
-uv.lock
+uv.lock
+
+# Claude Code artifacts
+CLAUDE.md
+.claude/