chore: finalize backend feature scope

tests/test_demo_flow.py

@@ -1,4 +1,5 @@
 import asyncio
+import json
 import os
 import sys
 import tempfile
@@ -37,6 +38,21 @@ from app.services.session_service import SessionService
 from scripts.init_demo_db import init_database
 
 
+async def collect_stream_reply(session_service: SessionService, ctx: UserContext, session_id: int, message: str) -> str:
+    """测试辅助：消费流式问诊 SSE，提取 AI 病人增量文本。"""
+    stream = await session_service.stream_chat(ctx, session_id, message)
+    reply = ""
+    done = False
+    async for event in stream:
+        if event.startswith("event: message_delta"):
+            payload_text = event.split("data:", 1)[1].strip()
+            reply += json.loads(payload_text)["delta"]
+        if event.startswith("event: message_done"):
+            done = True
+    assert done is True
+    return reply
+
+
 async def run_demo_flow() -> None:
     """完整闭环：验证第一版 Demo 的核心训练链路可跑通。"""
     init_database()
@@ -69,9 +85,9 @@ async def run_demo_flow() -> None:
         assert created.status == "inquiry"
         assert created.patient_config["labels"]["visit_environment"] == "门诊"
 
-        chat = await session_service.chat(ctx, created.session_id, ChatRequest(message="孩子最高体温多少？").message)
+        chat_reply = await collect_stream_reply(session_service, ctx, created.session_id, ChatRequest(message="孩子最高体温多少？").message)
         db.commit()
-        assert chat.reply
+        assert chat_reply
 
         order = order_service.create_order(created.session_id, ctx.user_id, CreateOrderRequest(item_code="chest_xray").item_code)
         db.commit()
@@ -136,7 +152,7 @@ async def run_demo_flow() -> None:
         assert treatment.status == "evaluating"
 
         try:
-            await session_service.chat(ctx, created.session_id, "治疗后还能问诊吗？")
+            await session_service.stream_chat(ctx, created.session_id, "治疗后还能问诊吗？")
         except AppError as exc:
             assert exc.code == "SESSION_STATUS_INVALID"
         else: