fix(ai): suppress sealed slo watchdog meta noise

apps/api/src/jobs/ai_slo_watchdog_job.py

@@ -118,11 +118,18 @@ async def _check_once() -> None:
         report = await AiSloCalculator().calculate()
         if report.any_violated:
             violated = [m.name for m in report.metrics if m.violated]
-            w1_line, w1_cause = _format_slo_violation_for_alert(report, violated)
-            violations.append(w1_line)
-            if w1_cause:
-                probable_causes.append(w1_cause)
-            violation_codes.append(f"W1:slo_violated:{','.join(sorted(violated))}")
+            if _is_observation_only_slo_violation(report, violated):
+                logger.info(
+                    "watchdog_w1_slo_observation_only",
+                    violated=violated,
+                    reason="sealed_waiting_rolling_window",
+                )
+            else:
+                w1_line, w1_cause = _format_slo_violation_for_alert(report, violated)
+                violations.append(w1_line)
+                if w1_cause:
+                    probable_causes.append(w1_cause)
+                violation_codes.append(f"W1:slo_violated:{','.join(sorted(violated))}")
     except Exception as e:
         logger.warning("watchdog_w1_slo_check_failed", error=str(e))
 
@@ -354,6 +361,23 @@ def _format_slo_violation_for_alert(report, violated: list[str]) -> tuple[str, s
     return line, "\n".join(cause_parts)
 
 
+def _is_observation_only_slo_violation(report, violated: list[str]) -> bool:
+    """已封口且只等 rolling window 的 W-1，不再升成 Meta System 告警。"""
+    if set(violated) != {"auto_execute_success_rate"}:
+        return False
+
+    diagnostics = getattr(report, "diagnostics", {}) or {}
+    diag = diagnostics.get("auto_execute_success_rate") or {}
+    try:
+        open_groups = int(diag.get("open_failure_group_count") or 0)
+    except (TypeError, ValueError):
+        open_groups = 0
+    return (
+        diag.get("status") == "sealed_waiting_window"
+        and open_groups == 0
+    )
+
+
 def _short_taipei_time(value: str | None) -> str | None:
     if not value:
         return None