Add WeCom markdown alerts and keep target exits while strategy is paused.

Notify open/close/start/pause/fault with SIM vs LIVE venue labels; configure webhook in Settings.

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

backend/tests/test_wecom_notify.py

@@ -0,0 +1,20 @@
+from __future__ import annotations
+
+from app.notify.wecom import TAG_OPEN, build_markdown, venue_label
+
+
+def test_build_markdown_has_tag_and_title(monkeypatch):
+    monkeypatch.setattr("app.notify.wecom.venue_label", lambda: "模拟盘")
+    md = build_markdown(tag=TAG_OPEN, title="开仓成功", lines=["组: G-1"])
+    assert "【模拟盘】开仓成功" in md
+    assert "`OPEN`" in md
+    assert "组: G-1" in md
+
+
+def test_venue_label_sim(monkeypatch):
+    class S:
+        is_sim = True
+        exchange = "okx"
+
+    monkeypatch.setattr("app.notify.wecom.get_settings", lambda: S())
+    assert venue_label() == "模拟盘"