feat(nav): Implement historical NAV tracking and enhance product API

- Added `list_nav_history` method in `CoreReadOnlyRepository` to retrieve historical NAV data for products over a specified number of days.
- Introduced `get_nav_history` endpoint in `product_service` to return historical NAV sequences, improving product data accessibility.
- Updated `products.py` to include new API endpoint for fetching NAV history, ensuring compliance with access control.
- Enhanced `ready.py` to include a health check for the new functionality, ensuring system readiness.
- Updated documentation to reflect the new testing baseline of 833 passed tests, indicating improved stability and functionality across the application.

This update significantly enhances the product API by providing access to historical NAV data, improving user insights into product performance.

docs/memory/TODO.md

@@ -60,7 +60,7 @@
 
 - [ ] **前端进页转圈**：batch 净值 API 或合并请求 · 客户端 stale-while-revalidate（见 `FRONTEND-HANDOFF.md` §10）
 - [ ] **看板演示口径**：四角色 `/app/{role}/home` 有图表；无 BI 大屏 · D-12 钻取仍 open
-- [ ] **客户持仓产品趋势（若要做）**：拍板 Chat 历史 nav Tool vs 问数引导 · 现状 §9.6 仅问数 `self` 域
+- [ ] **客户持仓产品趋势（若要做）**：拍板 Chat 历史 nav Tool vs 问数引导 · **平台行情详情已接 Core 历史** · Chat §9.6 仍仅问数 `self` 域
 
 ### 需拍板（定了再开任务）
 
@@ -260,7 +260,7 @@
 ### 客服 Agent · Wave3 开放项（2026-09-10 后）
 
 - [x] **C-04 push/cron（演示最小）**：`POST .../threshold-check?push=` · `scripts/demo/push_threshold_alerts.py` · 持仓页「检查阈值提醒」
-- [ ] **C-05 Phase B**：`nav-snapshot` sync · 前端行情 Phase B（见 v0.2 草案）
+- [ ] **C-05 Phase B**：`nav-snapshot` **外部 sync**（Core 内 **07 历史种子 + nav/history API + 详情页** 已做 · 见 v0.2 草案）
 - [ ] **C-08 偏离检测**：仅 L1 槽位，无自动调仓建议
 - [ ] **Vitest**：客户 Chat 新 intent 无前端单测（后端已覆盖）
 - [ ] **手工验收 + TEST-LOG 签核**（见上方「本批次 · 优先收尾」）