The timesheet log carried neither site nor project_code; attribution was
synthesised at read time from employees.site, so moving a worker to
another site silently migrated their entire payroll history with them.
docs/data-model.md flags this as the schema's worst drift risk.
Adds an optional site relation (maxSelect 1, cascadeDelete false so
deleting a site cannot destroy payroll history) and stamps all 1367 rows
from the employee's current site. 1367/1367 written, 0 orphans.
Tightened to required in Task 16, once the import route writes it on
every new row.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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