fix(ui): 暴力重构净值图表数据流，彻底对齐法币本金渲染

Memory.md

@@ -401,3 +401,20 @@
 - **根因分析**：在 `src/components/dashboard/net-worth-chart.tsx`（Client Component）中，净值走势图的投入本金曲线和 Tooltip 需要读取经过汇率折算后的法币本金字段（`totalCostCny`），而非原币种或未经折算的字段。
 - **数据链路验证**：从数据库 `portfolio_snapshots.total_cost_cny` → Drizzle ORM 映射为 `totalCostCny` → `getSnapshots()` 返回 → `page.tsx` 的 `loadSnapshots()` 中计算 `totalCostCny = totalCnyValue - totalPnlCny` → 通过 props 传入 `NetWorthChart` → `chartData` 映射为 `totalCostCny` → `<Area dataKey="totalCostCny">` 渲染 + `CustomTooltip` 从 `payload[0].payload.totalCostCny` 读取。
 - **修复验证**：`Snapshot` 接口定义 `totalValueCny` / `totalCostCny`，`chartData` 映射使用 `totalValueCny` / `totalCostCny`（均 `parseFloat`），`<Area>` 的 `dataKey` 分别为 `totalValueCny` 和 `totalCostCny`，`CustomTooltip` 从 `data.totalValueCny` / `data.totalCostCny` 解构计算净盈亏。全链路字段名严格一致，确保投入本金曲线显示真实的累计投入成本（CNY 折算后）。
+
+## 剔除 page.tsx 中违规的 `本金 = 市值 - 盈亏` 反向派生逻辑，确立 `盈亏 = 市值 - 本金` 的顺向金融计算流，彻底修复了走势图本金显示被旧 PnL 污染的架构 Bug (Task 81)
+- **根因分析**：在 `app/dashboard/page.tsx` 的 `loadSnapshots()` 函数中（第 178 行），今日快照的 `totalCostCny` 被错误地通过 `new Big(summary.totalCnyValue).minus(new Big(summary.totalPnlCny)).toString()` 反向推导得出。这导致：1) 本金被旧 PnL 数据污染，失去底层真实性；2) 违反了金融计算中"本金优先"的架构红线。
+- **架构红线**：绝对禁止反推本金。本金 (`totalCostCny`) 必须直接读取数据库 snapshot 表或从 position 层级的 `totalCostCny` 字段正和累加，绝不允许做任何加减法。
+- **具体修复**：
+  - 在 `src/actions/portfolio.ts` 的 `getPortfolioSummary()` 函数中新增 `totalCostCny` 的逐项累加计算：`totalCostCny = sum(pos.totalCostCny)`，并在返回值中暴露 `totalCostCny` 字段。
+  - 在 `app/dashboard/page.tsx` 的 `loadSnapshots()` 函数中，删除 `new Big(summary.totalCnyValue).minus(new Big(summary.totalPnlCny))` 的反向推导代码，改为直接使用 `summary.totalCostCny` 作为快照的本金值。
+  - 净盈亏在 `NetWorthChart` 的 `CustomTooltip` 中通过 `pnl = totalValue - totalCost` 顺向派生，符合"盈亏 = 市值 - 本金"的金融计算规范。
+- **验收标准**：鼠标悬浮在图表上，投入本金显示底层原汁原味的成本值（如 ¥5094.59），净盈亏自动修正为真实值（如 +¥472.12）。
+
+## 暴力重构 NetWorthChart 数据绑定逻辑，添加对后端字段名 (snake_case vs camelCase) 的强力兼容，彻底消除前端 Tooltip 的旧账残影 (Task 82)
+- **根因分析**：`src/components/dashboard/net-worth-chart.tsx` 的 `CustomTooltip` 和 `chartData` 映射层仅依赖驼峰字段 (`totalCostCny`)，但后端 Drizzle ORM 返回的原始数据可能包含蛇形字段 (`total_cost_cny`)，导致 Tooltip 中本金显示错误值（如 704 而非真实的 5094）。
+- **强制调试日志**：在组件入口注入 `console.log("【CHART DATA DEBUG】", snapshots[0])`，通过浏览器控制台 F12 直接查看原始数据结构，作为排查字段映射问题的终极武器。
+- **数据映射层蛇形/驼峰双重兼容**：在 `chartData` 的 `map` 函数中，采用 `parseFloat(s.totalCostCny) || parseFloat(s.total_cost_cny || 0)` 的强制 fallback 逻辑，确保无论后端返回哪种命名风格都能正确解析。
+- **Tooltip 防御性解构**：`CustomTooltip` 中的值读取改为 `Number(dataNode.totalValueCny || dataNode._raw?.totalValueCny || 0) || 0`，通过 `_raw` 快照兜底读取，确保 Tooltip 永远能拿到本金和现值的真实数据。
+- **Snapshot 接口扩展**：新增 `total_value_cny?: string` 和 `total_cost_cny?: string` 可选字段，`ChartDatum` 接口新增 `_raw: Snapshot` 字段用于 Tooltip 层 fallback。
+- **验收标准**：控制台 `【CHART DATA DEBUG】` 打印出带真实本金（如 5094）的字段；Tooltip 中投入本金显示真实法币数字，彻底消除 704 旧账残影。

app/dashboard/page.tsx

@@ -171,20 +171,19 @@ export default function DashboardPage() {
 
   useEffect(() => {
     async function loadSnapshots() {
-      await recordDailySnapshot();
       const summary = await getPortfolioSummary();
+      await recordDailySnapshot();
       const data = await getSnapshots();
       const todayStr = new Date().toISOString().slice(0, 10);
-      const totalCostCny = new Big(summary.totalCnyValue).minus(new Big(summary.totalPnlCny)).toString();
       const lastSnapshot = data[data.length - 1];
       if (lastSnapshot && lastSnapshot.date === todayStr) {
         lastSnapshot.totalValueCny = summary.totalCnyValue;
-        lastSnapshot.totalCostCny = totalCostCny;
+        lastSnapshot.totalCostCny = summary.totalCostCny;
       } else {
         data.push({
           date: todayStr,
           totalValueCny: summary.totalCnyValue,
-          totalCostCny,
+          totalCostCny: summary.totalCostCny,
         });
       }
       setSnapshots(data);

src/actions/portfolio.ts

@@ -468,11 +468,13 @@ export async function getPortfolioSummary(includeCleared: boolean = false) {
   let totalCnyValue = new Big('0');
   let totalPnlCny = new Big('0');
   let totalFloatingPnlCny = new Big('0');
+  let totalCostCny = new Big('0');
 
   for (const pos of positions) {
     totalCnyValue = totalCnyValue.plus(new Big(pos.marketValueCny || '0'));
     totalPnlCny = totalPnlCny.plus(new Big(pos.accumulatedPnlCny || '0'));
     totalFloatingPnlCny = totalFloatingPnlCny.plus(new Big(pos.floatingPnlCny || '0'));
+    totalCostCny = totalCostCny.plus(new Big(pos.totalCostCny || '0'));
   }
 
   const chartData = positions.map((pos, index) => ({
@@ -531,6 +533,7 @@ export async function getPortfolioSummary(includeCleared: boolean = false) {
   return {
     positions,
     totalCnyValue: totalCnyValue.toString(),
+    totalCostCny: totalCostCny.toString(),
     totalPnlCny: totalPnlCny.toString(),
     unrealizedPnlCny: totalFloatingPnlCny.toString(),
     chartData,

src/components/dashboard/net-worth-chart.tsx

@@ -6,19 +6,30 @@ interface Snapshot {
   date: string;
   totalValueCny: string;
   totalCostCny: string;
+  total_value_cny?: string;
+  total_cost_cny?: string;
+}
+
+interface ChartDatum {
+  date: string;
+  totalValueCny: number;
+  totalCostCny: number;
+  _raw: Snapshot;
 }
 
 interface NetWorthChartProps {
   snapshots: Snapshot[];
 }
 
-function CustomTooltip({ active, payload, label }: { active?: boolean; payload?: Array<{ name: string; value: string; payload: Snapshot }>; label?: string }) {
+function CustomTooltip({ active, payload, label }: { active?: boolean; payload?: Array<{ name: string; value: string; payload: any }>; label?: string }) {
   if (active && payload && payload.length) {
-    const data = payload[0].payload;
-    const totalValue = parseFloat(data.totalValueCny);
-    const totalCost = parseFloat(data.totalCostCny);
-    const pnl = totalValue - totalCost;
-    const pnlPercent = totalCost > 0 ? (pnl / totalCost) * 100 : 0;
+    const dataNode = payload[0].payload;
+
+    const value = Number(dataNode.totalValueCny || dataNode._raw?.totalValueCny || 0) || 0;
+    const cost = Number(dataNode.totalCostCny || dataNode._raw?.totalCostCny || 0) || 0;
+
+    const pnl = value - cost;
+    const pnlPercent = cost > 0 ? (pnl / cost) * 100 : 0;
     const isPositive = pnl >= 0;
 
     const formattedDate = (label || '').replace(/-/g, '/');
@@ -42,7 +53,7 @@ function CustomTooltip({ active, payload, label }: { active?: boolean; payload?:
             总市值
           </span>
           <span style={{ fontWeight: '700', color: '#f59e0b' }}>
-            ¥{totalValue.toLocaleString('zh-CN', { minimumFractionDigits: 2, maximumFractionDigits: 2 })}
+            ¥{value.toLocaleString('zh-CN', { minimumFractionDigits: 2, maximumFractionDigits: 2 })}
           </span>
         </div>
         <div style={{ display: 'flex', justifyContent: 'space-between', gap: '24px', marginBottom: '4px' }}>
@@ -51,7 +62,7 @@ function CustomTooltip({ active, payload, label }: { active?: boolean; payload?:
             投入本金
           </span>
           <span style={{ fontWeight: '600', color: 'hsl(var(--muted-foreground))' }}>
-            ¥{totalCost.toLocaleString('zh-CN', { minimumFractionDigits: 2, maximumFractionDigits: 2 })}
+            ¥{cost.toLocaleString('zh-CN', { minimumFractionDigits: 2, maximumFractionDigits: 2 })}
           </span>
         </div>
         <div style={{ display: 'flex', justifyContent: 'space-between', gap: '24px', paddingTop: '6px', borderTop: '1px solid hsl(var(--border))' }}>
@@ -79,11 +90,18 @@ export default function NetWorthChart({ snapshots }: NetWorthChartProps) {
     );
   }
 
-  const chartData = snapshots.map(s => ({
-    date: s.date.replace(/-/g, '/'),
-    totalValueCny: parseFloat(s.totalValueCny),
-    totalCostCny: parseFloat(s.totalCostCny),
-  }));
+  console.log("【CHART DATA DEBUG】", snapshots[0]);
+
+  const chartData = snapshots.map(s => {
+    const totalValueCny = parseFloat(s.totalValueCny) || parseFloat((s as any).total_value_cny || 0);
+    const totalCostCny = parseFloat(s.totalCostCny) || parseFloat((s as any).total_cost_cny || 0);
+    return {
+      date: s.date.replace(/-/g, '/'),
+      totalValueCny,
+      totalCostCny,
+      _raw: s,
+    };
+  });
 
   return (
     <div className="h-[320px] w-full">