refactor(backend): update financial record model, schema and expense claims

- models/financial_record.py: update financial record model
- schemas/reimbursement.py: update reimbursement schema
- services/expense_claims.py: update expense claims service

server/src/app/models/financial_record.py

@@ -44,6 +44,7 @@ class ExpenseClaim(Base):
         DateTime(timezone=True), server_default=func.now(), onupdate=func.now()
     )
 
+    employee = relationship("Employee", foreign_keys=[employee_id])
     items = relationship(
         "ExpenseClaimItem",
         back_populates="claim",
@@ -51,6 +52,28 @@ class ExpenseClaim(Base):
         order_by="asc(ExpenseClaimItem.item_date)",
     )
 
+    @property
+    def employee_position(self) -> str | None:
+        return str(self.employee.position).strip() if self.employee is not None and self.employee.position else None
+
+    @property
+    def employee_grade(self) -> str | None:
+        return str(self.employee.grade).strip() if self.employee is not None and self.employee.grade else None
+
+    @property
+    def manager_name(self) -> str | None:
+        if self.employee is None:
+            return None
+        if self.employee.manager is not None and self.employee.manager.name:
+            return str(self.employee.manager.name).strip() or None
+        return None
+
+    @property
+    def role_labels(self) -> list[str]:
+        if self.employee is None or not self.employee.roles:
+            return []
+        return [str(role.name).strip() for role in sorted(self.employee.roles, key=lambda item: item.name) if role.name]
+
 
 class ExpenseClaimItem(Base):
     __tablename__ = "expense_claim_items"