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/schemas/reimbursement.py

@@ -91,6 +91,10 @@ class ExpenseClaimRead(BaseModel):
     employee_name: str
     department_id: str | None
     department_name: str
+    employee_position: str | None = None
+    employee_grade: str | None = None
+    manager_name: str | None = None
+    role_labels: list[str] = Field(default_factory=list)
     project_code: str | None
     expense_type: str
     reason: str