StockTrade 컴포넌트 훅 분리 (Phase 4): 2,788→1,932줄

8개 커스텀 훅으로 state/handler 로직 추출:
- usePortfolio: 포트폴리오 CRUD, 예수금, 브로커 그룹
- useSellHistory: 매도 내역 CRUD, 드로어/폼 상태
- useAiCoach: AI 코치 분석 + 캐시
- useAssetHistory: 자산 추이 차트 데이터
- useMarketContext: VIX/F&G/국채/WTI 시장 데이터
- useAiBalance: AI 모의투자 잔고, 수동 주문
- useReportData: 리포트 정렬, 차트, 집중도 분석
- useAdvisor: 어드바이저 프롬프트 빌더

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/pages/stock/hooks/useAssetHistory.js

@@ -0,0 +1,66 @@
+import { useState, useCallback } from 'react';
+import { getAssetHistory, saveAssetSnapshot } from '../../../api';
+
+export default function useAssetHistory() {
+    const [assetHistory, setAssetHistory] = useState(null);
+    const [assetHistoryLoading, setAssetHistoryLoading] = useState(false);
+    const [assetHistoryDays, setAssetHistoryDays] = useState(30);
+    const [snapshotSaving, setSnapshotSaving] = useState(false);
+
+    const loadAssetHistory = useCallback(async (days) => {
+        setAssetHistoryLoading(true);
+        try {
+            const data = await getAssetHistory(days);
+            const raw = data?.snapshots ?? data?.history ?? (Array.isArray(data) ? data : []);
+            const byDate = {};
+            for (const item of raw) byDate[item.date] = item.total_assets ?? 0;
+
+            const toLocalDate = (d) => {
+                const y = d.getFullYear();
+                const m = String(d.getMonth() + 1).padStart(2, '0');
+                const day = String(d.getDate()).padStart(2, '0');
+                return `${y}-${m}-${day}`;
+            };
+
+            let filled;
+            if (days > 0) {
+                const today = new Date();
+                filled = Array.from({ length: days }, (_, i) => {
+                    const d = new Date(today);
+                    d.setDate(today.getDate() - (days - 1 - i));
+                    const dateStr = toLocalDate(d);
+                    const val = byDate[dateStr];
+                    return val > 0 ? { date: dateStr, total_assets: val } : null;
+                }).filter(Boolean);
+            } else {
+                filled = Object.entries(byDate)
+                    .filter(([, v]) => v > 0)
+                    .map(([date, total_assets]) => ({ date, total_assets }))
+                    .sort((a, b) => a.date.localeCompare(b.date));
+            }
+            setAssetHistory(filled);
+        } catch {
+            setAssetHistory([]);
+        } finally {
+            setAssetHistoryLoading(false);
+        }
+    }, []);
+
+    const handleSaveSnapshot = async (totalAssets, days) => {
+        setSnapshotSaving(true);
+        try {
+            await saveAssetSnapshot(totalAssets != null ? Number(totalAssets) : undefined);
+            await loadAssetHistory(days);
+        } catch (err) {
+            alert('스냅샷 저장 실패: ' + (err?.message ?? String(err)));
+        } finally {
+            setSnapshotSaving(false);
+        }
+    };
+
+    return {
+        assetHistory, assetHistoryLoading,
+        assetHistoryDays, setAssetHistoryDays,
+        snapshotSaving, loadAssetHistory, handleSaveSnapshot,
+    };
+}