chore: Add dev-cleaner binary to .gitignore

Author: thanhdevapp

.gitignore

@@ -69,6 +69,9 @@ test-ck
 __pycache__
 prompt.md
 
+# Go binary
+dev-cleaner
+
 # Gemini CLI settings (symlink to .claude/.mcp.json)
 .gemini/settings.json
 .claude/settings.bak.json