Expose sim/live matching mode in env config UI.

Saving SIM_DEFAULT_MODE also switches runtime trading.mode immediately.

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

lib/instance/runtime_config_lib.py

@@ -51,12 +51,26 @@ def apply_env_reload(env_path: str, get_db: Callable, changed_keys: list[str], g
             field_map[field["key"]] = field
     for key in changed_keys:
         meta = field_map.get(key) or {}
-        if meta.get("hot_reload") and not meta.get("restart_required"):
+        # SIM_DEFAULT_MODE 不在 example schema 的 hot 列表时仍应热切
+        is_hot = bool(meta.get("hot_reload") and not meta.get("restart_required"))
+        if key == "SIM_DEFAULT_MODE":
+            is_hot = True
+        if is_hot:
             val = os.getenv(key)
             if val is not None:
                 hot[key] = val
     if hot:
         set_config_overrides(get_db, hot)
+    # 撮合模式:写入 .env 的同时切换运行时 trading.mode(sim|live)
+    if "SIM_DEFAULT_MODE" in changed_keys:
+        try:
+            from lib.sim.mode_lib import set_trading_mode
+
+            raw = (os.getenv("SIM_DEFAULT_MODE") or "").strip().lower()
+            if raw in ("sim", "live"):
+                set_trading_mode(get_db, raw)
+        except Exception:
+            pass
     from lib.env.env_schema import updates_need_restart
 
     return {"restart_required": updates_need_restart(groups, changed_keys)}