Fix recovery Telegram dedup and unify Beijing time display.

Store alert metrics without per-value Redis members to stop duplicate recovery pushes; format all operator-facing timestamps in Asia/Shanghai across Web UI and Telegram.

tests/test_telegram_time_format.py

@@ -0,0 +1,19 @@
+"""Telegram timestamps should display Beijing local time."""
+
+from datetime import datetime
+from zoneinfo import ZoneInfo
+
+from server.infrastructure.telegram import _now_cn
+from server.utils.display_time import format_beijing_now
+
+
+def test_now_cn_uses_beijing_timezone_label():
+    text = _now_cn()
+    assert text == format_beijing_now()
+    assert text.endswith("北京时间")
+    assert "UTC" not in text
+    wall = text.replace(" 北京时间", "")
+    parsed = datetime.strptime(wall, "%Y-%m-%d %H:%M:%S").replace(tzinfo=ZoneInfo("Asia/Shanghai"))
+    utc_now = datetime.now(ZoneInfo("UTC"))
+    delta_seconds = abs((parsed - utc_now).total_seconds())
+    assert delta_seconds < 120