Plug-in modules via new datasets

Plug-in modules via new datasets

BusDK supports adding modules by defining new datasets and schemas and implementing tooling that reads and writes them. A payroll module is a canonical example: workspace-root datasets such as employees.csv, payruns.csv, payments.csv, and posting_accounts.csv (with beside-the-table schemas) can be validated and exported with bus payroll validate and bus payroll export pr-001 to generate deterministic posting rows for journal workflows. This extension does not require modifications to existing modules as long as it follows existing schema and reference contracts.