feat(expenses): add transactional expense case events

server/src/app/schemas/expense_case.py

@@ -0,0 +1,51 @@
+from __future__ import annotations
+
+from datetime import datetime
+from typing import Any
+
+from pydantic import BaseModel, ConfigDict, Field
+
+
+class ExpenseCaseLinkRead(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
+    id: str
+    resource_type: str
+    resource_id: str
+    relation_type: str
+    created_at: datetime
+
+
+class BusinessEventRead(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
+    id: str
+    event_type: str
+    event_version: int
+    idempotency_key: str
+    aggregate_type: str
+    aggregate_id: str
+    correlation_id: str
+    causation_id: str | None
+    actor_id: str
+    actor_type: str
+    payload_json: dict[str, Any] = Field(default_factory=dict)
+    delivery_status: str
+    occurred_at: datetime
+    published_at: datetime | None
+
+
+class ExpenseCaseTimelineRead(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
+    id: str
+    case_no: str
+    scene_code: str
+    title: str
+    owner_employee_id: str | None
+    current_stage: str
+    status: str
+    created_at: datetime
+    updated_at: datetime
+    links: list[ExpenseCaseLinkRead] = Field(default_factory=list)
+    events: list[BusinessEventRead] = Field(default_factory=list)