feat: 计仓改为固定手数/固定金额，推荐过滤与CTP保证金，下单与持仓UI优化

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

app.py

@@ -372,7 +372,11 @@ def init_db():
     if not get_setting("trading_mode"):
         set_setting("trading_mode", "simulation")
     if not get_setting("position_sizing_mode"):
-        set_setting("position_sizing_mode", "risk")
+        set_setting("position_sizing_mode", "fixed")
+    if not get_setting("fixed_lots"):
+        set_setting("fixed_lots", "1")
+    if not get_setting("fixed_amount"):
+        set_setting("fixed_amount", "5000")
     if not get_setting("risk_percent"):
         set_setting("risk_percent", "1")
     if not get_setting("max_margin_pct"):
@@ -755,7 +759,13 @@ def api_symbols_mains():
 def api_symbols_recommended():
     """品种下拉：仅展示当前资金下推荐的品种（与下方品种推荐表一致）。"""
     from recommend_store import recommend_payload
-    from trading_context import get_account_capital, get_max_margin_pct
+    from trading_context import (
+        get_account_capital,
+        get_fixed_lots,
+        get_max_margin_pct,
+        get_sizing_mode,
+        get_trading_mode,
+    )
 
     conn = get_db()
     try:
@@ -764,6 +774,9 @@ def api_symbols_recommended():
             conn,
             live_capital=capital,
             max_margin_pct=get_max_margin_pct(get_setting),
+            trading_mode=get_trading_mode(get_setting),
+            sizing_mode=get_sizing_mode(get_setting),
+            fixed_lots=get_fixed_lots(get_setting),
         )
         return jsonify(list_recommended_symbols_grouped(payload.get("rows") or []))
     finally:
@@ -1639,17 +1652,30 @@ def settings():
             mode = request.form.get("trading_mode", "simulation").strip()
             if mode not in ("simulation", "live"):
                 mode = "simulation"
-            sizing = request.form.get("position_sizing_mode", "risk").strip()
-            if sizing not in ("fixed", "risk"):
-                sizing = "risk"
+            sizing = request.form.get("position_sizing_mode", "fixed").strip()
+            if sizing == "risk":
+                sizing = "amount"
+            if sizing not in ("fixed", "amount"):
+                sizing = "fixed"
             set_setting("trading_mode", mode)
             set_setting("position_sizing_mode", sizing)
+            try:
+                fl = int(float(request.form.get("fixed_lots", "1") or 1))
+                set_setting("fixed_lots", str(max(1, fl)))
+            except ValueError:
+                flash("固定手数无效")
+                return redirect(url_for("settings"))
+            try:
+                fa = float(request.form.get("fixed_amount", "5000") or 5000)
+                set_setting("fixed_amount", str(max(1.0, fa)))
+            except ValueError:
+                flash("固定金额无效")
+                return redirect(url_for("settings"))
             try:
                 rp = float(request.form.get("risk_percent", "1") or 1)
                 set_setting("risk_percent", str(max(0.1, min(100.0, rp))))
             except ValueError:
-                flash("风险比例无效")
-                return redirect(url_for("settings"))
+                pass
             try:
                 mp = float(request.form.get("max_margin_pct", "30") or 30)
                 set_setting("max_margin_pct", str(max(1.0, min(100.0, mp))))
@@ -1699,7 +1725,9 @@ def settings():
         username=username,
         quote_label=get_quote_source_label(ctp_connected=bool(ctp_st.get("connected"))),
         trading_mode=get_setting("trading_mode", "simulation"),
-        position_sizing_mode=get_setting("position_sizing_mode", "risk"),
+        position_sizing_mode=get_setting("position_sizing_mode", "fixed"),
+        fixed_lots=get_setting("fixed_lots", "1"),
+        fixed_amount=get_setting("fixed_amount", "5000"),
         risk_percent=get_setting("risk_percent", "1"),
         max_margin_pct=get_setting("max_margin_pct", "30"),
         trailing_be_tick_buffer=get_setting("trailing_be_tick_buffer", "2"),