fix(sre): type backup alerts before generic routing

apps/api/tests/test_classify_alert_early.py

@@ -63,15 +63,43 @@ class TestInfoAlerts:
         assert ac == "info"
 
     def test_backup_keyword_info_only(self):
-        # severity=info → severity 規則先命中，TYPE-1
+        # 成功通知仍是 TYPE-1，但不可丟失備份領域分類。
         ac, nt = classify_alert_early("BackupJobComplete", "info", {})
+        assert ac == "backup_restore"
         assert nt == "TYPE-1"
 
     def test_backup_keyword_warning_not_type1(self):
-        # BackupJobFailed severity=warning → 繼續走 prefix 規則，不應是 TYPE-1
+        # 備份失敗立即進唯讀 BackupCheck，不等 24 小時。
         ac, nt = classify_alert_early("BackupJobFailed", "warning", {})
+        assert ac == "backup_restore"
         assert nt == "TYPE-3"
 
+    @pytest.mark.parametrize(
+        "alertname",
+        (
+            "Backup.awoooi-frequent",
+            "Backup.langfuse",
+            "Backup.signoz",
+            "HostBackupFailed",
+            "BackupCredentialEscrowEvidenceMissing",
+        ),
+    )
+    def test_backup_products_share_typed_readback_domain(self, alertname):
+        ac, nt = classify_alert_early(alertname, "warning", {})
+        assert (ac, nt) == ("backup_restore", "TYPE-3")
+
+    def test_backup_domain_label_routes_even_without_backup_alertname(self):
+        ac, nt = classify_alert_early(
+            "DataProtectionEvidenceMissing",
+            "critical",
+            {"asset_domain": "backup_restore"},
+        )
+        assert (ac, nt) == ("backup_restore", "TYPE-3")
+
+    def test_generic_service_restored_is_not_a_backup_identity(self):
+        ac, nt = classify_alert_early("ServiceRestored", "info", {})
+        assert (ac, nt) == ("info", "TYPE-1")
+
     def test_watchdog_heartbeat(self):
         # Watchdog (Alertmanager 心跳) severity=none → severity 規則先命中，TYPE-1
         ac, nt = classify_alert_early("Watchdog", "none", {})
@@ -84,9 +112,9 @@ class TestInfoAlerts:
         assert nt == "TYPE-1"
 
     def test_backup_critical_not_type1(self):
-        # critical backup 告警應走各自 prefix，不是純資訊
+        # critical backup 告警必須是明確的備份領域唯讀調查。
         ac, nt = classify_alert_early("BACKUP_MISSING", "critical", {})
-        assert nt == "TYPE-3"
+        assert (ac, nt) == ("backup_restore", "TYPE-3")
 
 
 # --------------------------------------------------------------------------- #
@@ -270,10 +298,9 @@ class TestKubernetes:
         assert ac == "kubernetes"
 
     def test_velero_backup_failed_is_kubernetes(self):
-        # VeleroBackupFailed severity=critical → backup 規則不命中，走 Velero prefix → kubernetes TYPE-3
+        # Velero 備份是資料保護事件，不可誤掉到 K8s 寫入 executor。
         ac, nt = classify_alert_early("VeleroBackupFailed", "critical", {})
-        assert nt == "TYPE-3"
-        assert ac == "kubernetes"
+        assert (ac, nt) == ("backup_restore", "TYPE-3")
 
     def test_velero_backup_success_info_is_type1(self):
         # VeleroBackupSuccess severity=info → TYPE-1