feat: 优化界面并补充网格成交分析

tests/test_calculations.py

@@ -3,8 +3,13 @@ from decimal import Decimal
 
 import pytest
 
-from grid_trading.domain.calculations import CalculationError, calculate_positions, estimate_fees
-from grid_trading.domain.models import FeeRules, Instrument, QuoteSnapshot, Trade, TradeGroup, TradeSide
+from grid_trading.domain.calculations import (
+    CalculationError,
+    calculate_account_summary,
+    calculate_positions,
+    estimate_fees,
+)
+from grid_trading.domain.models import Account, FeeRules, Instrument, QuoteSnapshot, Trade, TradeGroup, TradeSide
 
 
 def make_trade(
@@ -175,6 +180,39 @@ def test_missing_quote_does_not_use_manual_or_last_trade_price_for_current_price
     assert summary.floating_pnl is None
 
 
+def test_account_summary_caps_capital_usage_when_cash_is_negative():
+    today = date(2026, 7, 8)
+    account = Account(id=1, name="主账户", initial_cash=Decimal("100"))
+    instrument = Instrument(id=1, code="600588", name="用友网络")
+    trades = [
+        make_trade(
+            trade_id=1,
+            trade_date=today,
+            side=TradeSide.BUY,
+            price="1.50",
+            quantity=100,
+            trade_group=TradeGroup.BASE,
+        )
+    ]
+    quotes = {
+        1: QuoteSnapshot(
+            symbol="sh600588",
+            code="600588",
+            name="用友网络",
+            price=Decimal("1.00"),
+            source="tencent",
+        )
+    }
+
+    positions = calculate_positions([instrument], trades, as_of=today, quote_snapshots=quotes)
+    summary = calculate_account_summary(account, positions, [], trades)
+
+    assert summary.cash == Decimal("-50.00")
+    assert summary.market_value == Decimal("100.00")
+    assert summary.total_assets == Decimal("50.00")
+    assert summary.capital_usage_rate == Decimal("1.0000")
+
+
 def test_sell_more_than_group_position_raises():
     today = date(2026, 7, 8)
     instrument = Instrument(id=1, code="159915", name="创业板ETF")