Remove ast.json files and skip tests when explain: false in metadata#9

kyleconroy merged 2 commits intomainsqlc-dev/doubleclick:mainfrom

claude/cleanup-ast-skip-tests-01691C2nR5zCfu4GV2EaHPycsqlc-dev/doubleclick:claude/cleanup-ast-skip-tests-01691C2nR5zCfu4GV2EaHPycCopy head branch name to clipboard