refactor(backend): update reimbursement and expense claims

- endpoints/reimbursements.py: update reimbursement API endpoint
- schemas/reimbursement.py: update reimbursement data schemas
- services/expense_claims.py: update expense claims service logic

server/src/app/schemas/reimbursement.py

@@ -1,9 +1,10 @@
 from __future__ import annotations
 
-from datetime import datetime
+from datetime import date, datetime
 from decimal import Decimal
+from typing import Any
 
-from pydantic import BaseModel, ConfigDict
+from pydantic import BaseModel, ConfigDict, Field
 
 
 class ReimbursementCreate(BaseModel):
@@ -28,3 +29,58 @@ class ReimbursementRead(BaseModel):
     reason: str | None
     created_at: datetime
     updated_at: datetime
+
+
+class ExpenseClaimItemRead(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
+    id: str
+    item_date: date
+    item_type: str
+    item_reason: str
+    item_location: str
+    item_amount: Decimal
+    invoice_id: str | None
+    created_at: datetime
+    updated_at: datetime
+
+
+class ExpenseClaimItemUpdate(BaseModel):
+    item_date: date | None = None
+    item_type: str | None = None
+    item_reason: str | None = None
+    item_location: str | None = None
+    item_amount: Decimal | None = None
+    invoice_id: str | None = None
+
+
+class ExpenseClaimRead(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
+    id: str
+    claim_no: str
+    employee_id: str | None
+    employee_name: str
+    department_id: str | None
+    department_name: str
+    project_code: str | None
+    expense_type: str
+    reason: str
+    location: str
+    amount: Decimal
+    currency: str
+    invoice_count: int
+    occurred_at: datetime
+    submitted_at: datetime | None
+    status: str
+    approval_stage: str | None
+    risk_flags_json: list[Any] = Field(default_factory=list)
+    created_at: datetime
+    updated_at: datetime
+    items: list[ExpenseClaimItemRead] = Field(default_factory=list)
+
+
+class ExpenseClaimActionResponse(BaseModel):
+    message: str
+    claim_id: str
+    status: str | None = None