fix(risk): align freeze countdown with latest close not stale 4h until

Pick the shortest active cooloff end and derive 1h/4h label from remaining time.

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

tests/test_account_risk_lib.py

@@ -214,6 +214,28 @@ class AccountRiskLibTests(unittest.TestCase):
         self.assertEqual(st["status"], STATUS_FREEZE_1H)
         self.assertEqual(st["cooloff_until_ms"], _local_ms(journal_at) + 3600 * 1000)
 
+    def test_stale_4h_until_with_1h_hours_uses_shorter_end(self):
+        """库内 cooloff_hours=1 但 cooloff_until_ms 仍为旧 4h 时，应按 last_close+1h 倒计时。"""
+        conn = _mem_conn()
+        now = datetime(2026, 6, 14, 12, 6, 0)
+        now_ms = _local_ms(now)
+        close_ms = now_ms - 6 * 60 * 1000
+        stale_until_4h = close_ms + 4 * 3600 * 1000
+        conn.execute(
+            """UPDATE account_risk_state SET
+               trading_day='2026-06-14',
+               manual_close_count=1,
+               cooloff_until_ms=?,
+               cooloff_hours=1,
+               last_close_at_ms=?,
+               daily_frozen=0
+               WHERE id=1""",
+            (stale_until_4h, close_ms),
+        )
+        st = compute_account_risk_status(conn, trading_day="2026-06-14", now=now)
+        self.assertEqual(st["status"], STATUS_FREEZE_1H)
+        self.assertAlmostEqual(st["freeze_remaining_sec"], 54 * 60, delta=3)
+
     def test_legacy_naive_utc_ms_countdown_normalized(self):
         conn = _mem_conn()
         now = datetime(2026, 6, 14, 12, 0, 0)