fix: AI 摘要 DeepSeek 配置修复

1. generate_summary 调用 get_light_board 补传 user_id/role
   (否则亮灯表数据为空, 摘要缺少覆盖分析)
2. AI_API_URL: /anthropic → /v1/chat/completions
   (原先 URL 不是 DeepSeek 标准 OpenAI 兼容端点)
3. AI_MODEL: deepseek-v4-flash → deepseek-chat
   (原模型名不是已知的 DeepSeek 模型)

backend/app/services/ai_summary.py

@@ -160,7 +160,7 @@ async def generate_summary(
     weekly_report = await get_weekly_report(
         db=db, user_id=user_id, role=role, reference_date=ref,
     )
-    light_board = await get_light_board(db, ref)
+    light_board = await get_light_board(db, ref, user_id, role)
     user_prompt = build_summary_prompt(weekly_report, light_board, period, str(ref))
 
     # Call LLM