Retrofits Request.employeeId from a free-text String with no
referential integrity to a real relation: employeeId String @db.Uuid
+ employee Employee @relation(...), plus the inverse Employee.requests
back-relation field. Migration alters requests.employee_id from TEXT
to UUID with an FK constraint (drop+recreate, confirmed empty table -
no production/dev data existed to migrate).
Employee directory entity per docs/asset-license-management.md's data
model table (id, name, department, manager). department stays a plain
String for now (not a separate Department entity). managerId is a
nullable self-relation (EmployeeManager) - top-level employees have
managerId = null.
toanhoang