feat(trader): live bridge token 改从 config 读取，免容器重建

容器 docker run（非 compose）注入 BRIDGE_TOKEN env 需重建容器，风险大。改为 live_cfg.bridge_token 优先、fallback BRIDGE_TOKEN env。run_live_step 每次 load_config，改 config 免重启即生效。

- _shadow_trades_to_bridge + reconcile_from_bridge 两处 token 读取
- config: live.bridge_token 占位空值（真实值填 NAS gitignored config，不入库）
- tests: +6 测试（config优先/env fallback/都无跳过），191 passed

tests/trader/test_shadow_orders.py

@@ -98,3 +98,46 @@ class TestShadowTradesToBridge:
                 "SELECT status FROM paper_shadow_orders WHERE account_id=1"
             ).fetchone()
         assert row and row[0] == "failed"
+
+
+class TestShadowTokenSource:
+    """bridge_token 优先级：config > env > skip（D-3 影子下单）。"""
+
+    def test_config_token_used(self, tmp_path):
+        """(a) config 有 bridge_token → 用 config token（env 未设）。"""
+        db = _mk_db(tmp_path)
+        _insert_trade(db)
+        cfg = SimpleNamespace(live={
+            "enabled": True, "bridge_url": "http://b.test", "shadow": True,
+            "bridge_token": "cfg-token",
+        })
+        with patch.dict("os.environ", {}, clear=True), \
+             patch("sanguo_trader.bridge_client.BridgeClient") as mbc:
+            mbc.return_value.place_order.return_value = {"ok": True, "order_id": 1}
+            _shadow_trades_to_bridge(db, 1, _DATE, cfg)
+            assert mbc.call_args[0][1] == "cfg-token"  # BridgeClient(url, token)
+
+    def test_env_fallback_when_config_missing(self, tmp_path):
+        """(b) config 无 bridge_token → fallback 到 BRIDGE_TOKEN env。"""
+        db = _mk_db(tmp_path)
+        _insert_trade(db)
+        cfg = SimpleNamespace(live={
+            "enabled": True, "bridge_url": "http://b.test", "shadow": True,
+        })
+        with patch.dict("os.environ", {"BRIDGE_TOKEN": "env-token"}), \
+             patch("sanguo_trader.bridge_client.BridgeClient") as mbc:
+            mbc.return_value.place_order.return_value = {"ok": True, "order_id": 1}
+            _shadow_trades_to_bridge(db, 1, _DATE, cfg)
+            assert mbc.call_args[0][1] == "env-token"
+
+    def test_no_token_skips(self, tmp_path):
+        """(c) config 和 env 都无 bridge_token → 跳过、warning，不下单。"""
+        db = _mk_db(tmp_path)
+        _insert_trade(db)
+        cfg = SimpleNamespace(live={
+            "enabled": True, "bridge_url": "http://b.test", "shadow": True,
+        })
+        with patch.dict("os.environ", {}, clear=True), \
+             patch("sanguo_trader.bridge_client.BridgeClient") as mbc:
+            _shadow_trades_to_bridge(db, 1, _DATE, cfg)
+            mbc.assert_not_called()