refactor(analyst): Update authentication context and add smoke test script

- Replaced `get_auth_context` with `get_platform_auth_context` in `analyst.py` to enhance authentication handling.
- Added a new smoke test script `smoke_analyst.py` for testing the data analysis agent with both fake and live LLM configurations.
- Updated TODO documentation to reflect the completion of Scope B smoke tests, ensuring clarity on testing status.

This update improves the authentication mechanism and introduces a comprehensive testing approach for the data analysis agent.

docs/memory/TODO.md

@@ -66,7 +66,7 @@
 - [x] **Wave6 测试**：`test_wave6_*` · +43 例
 - [x] **前端问数页**：`web/src/pages/analytics/AnalystQueryPage.tsx` · `api/analyst.ts`
 - [x] **迁移 SQL（本机）**：`scripts/agent/migrate-analyst-d07-d11.sql`（三资产表 · 2026-09-09 已执行 · **无种子数据**）
-- [ ] **Scope B 冒烟**：四 Demo 角色各一条问数（需 MySQL + 可选 DeepSeek Key）
+- [x] **Scope B 冒烟**：`python scripts/dev/smoke_analyst.py` → **19/19**（FakeLLM + `--live-llm` 真 MySQL/LLM 亦绿）
 
 ### 风控 Agent · 后端已就绪 · 前端/运维未接（盘点 2026-09-09）