Directory discovery (FindBeadsDir, findDatabaseInTree, FindAllDatabases)
now stops at the git repository root to avoid finding unrelated databases
in parent directories (e.g., ~/.beads).
Added findGitRoot() helper that uses 'git rev-parse --show-toplevel'.
Also updated TestCheckDatabaseVersionJSONLMode to properly simulate
no-db mode by creating config.yaml with 'no-db: true'.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>