fix: 全仓模式预估风险/盈利按杠杆与可用保证金计算

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_manual_order_rr_preview.py

@@ -37,3 +37,30 @@ def test_invalid_geometry_returns_none():
 def test_pct_mode_rr():
     assert _calc_rr_from_pct(2.0, 4.0) == 2.0
     assert _calc_rr_from_pct(1.5, 3.0) == 2.0
+
+
+def _calc_risk_fraction(direction: str, entry: float, sl: float):
+    if entry <= 0 or sl <= 0:
+        return None
+    if direction == "short":
+        risk = sl - entry
+    else:
+        risk = entry - sl
+    if risk <= 0:
+        return None
+    return risk / entry
+
+
+def _full_margin_risk_u(available: float, buffer: float, leverage: int, direction: str, entry: float, sl: float):
+    rf = _calc_risk_fraction(direction, entry, sl)
+    if rf is None:
+        return None
+    margin = round(available * buffer, 2)
+    return round(margin * leverage * rf, 2)
+
+
+def test_full_margin_risk_short_hype():
+    # 可用约 23.06U × 0.9 缓冲 × 5x，入场 62.5、止损 63.6
+    risk = _full_margin_risk_u(23.06, 0.9, 5, "short", 62.5, 63.6)
+    assert risk is not None
+    assert 1.5 <= risk <= 2.5