Models a manager as a Worker with a pay_type discriminator, reusing the
existing loan/adjustment/payslip/payroll pipeline. New 'Salary'
adjustment type, project-attributed; managers excluded from
attendance/absence pickers so daily-worker math is provably untouched.
HARD STOP after implementation for local verification before any push.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>