Add pre-buy expiry breakeven columns to options chain table.

Show estimated expiry balance and distance from index in the chain list and order panel using ask price before opening a position.

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

tests/test_options_pricing.py

@@ -67,6 +67,14 @@ def test_option_moneyness():
     assert option_moneyness_label("otm") == "虚值"
 
 
+def test_expiry_breakeven_from_ask():
+    from lib.options.options_pricing_lib import expiry_breakeven_from_ask
+
+    assert expiry_breakeven_from_ask(opt_type="C", strike=1760, ask_px=15.6) == 1775.6
+    assert expiry_breakeven_from_ask(opt_type="P", strike=1760, ask_px=15.6) == 1744.4
+    assert expiry_breakeven_from_ask(opt_type="C", strike=1760, ask_px=None, mark_px=14.2) == 1774.2
+
+
 def test_calc_order_size_too_small():
     r = calc_order_size(
         quote_per_unit=2000.0,