fix(api): restore converged alert recurrence notifications

apps/api/src/api/v1/webhooks.py

@@ -59,6 +59,9 @@ from src.services.channel_hub import (
     record_alertmanager_event,
     record_grouped_alert_event,
 )
+from src.services.converged_alert_recurrence_notifier import (
+    notify_converged_alert_recurrence,
+)
 
 # Phase 15.2: Trace Context (moved to SignalProducerService)
 # get_trace_context 已移至 Service 層
@@ -1148,15 +1151,29 @@ async def receive_alert(
                 # 避免 Telegram 洗版，用戶可在 UI 查看聚合次數
                 # =================================================================
                 logger.info(
-                    "alert_converged_telegram_skipped",
+                    "alert_converged_telegram_recurrence_scheduled",
                     approval_id=str(updated_approval.id),
                     hit_count=updated_approval.hit_count,
-                    reason="Converged alert - Telegram already sent for this fingerprint",
+                    reason="Converged alert - scheduling throttled recurrence notice",
+                )
+                background_tasks.add_task(
+                    notify_converged_alert_recurrence,
+                    source=alert.source,
+                    fingerprint=fingerprint,
+                    alertname=alert.alert_type,
+                    severity=alert.severity,
+                    namespace=alert.namespace,
+                    target_resource=alert.target_resource,
+                    hit_count=updated_approval.hit_count,
+                    incident_id=getattr(updated_approval, "incident_id", None),
+                    approval_id=str(updated_approval.id),
+                    alert_category=alert.alert_type,
+                    notification_type="generic",
                 )
 
                 return AlertResponse(
                     success=True,
-                    message=f"🛡️ 告警收斂 (x{updated_approval.hit_count}) - Telegram 已發送，跳過重複通知",
+                    message=f"🛡️ 告警收斂 (x{updated_approval.hit_count}) - 已排程節流再通知",
                     alert_id=alert_id,
                     approval_created=False,  # 未建立新卡片
                     approval_id=str(updated_approval.id),
@@ -2693,10 +2710,10 @@ async def alertmanager_webhook(
                 # 2026-03-27 ogt: 收斂告警不重複發送 Telegram，只更新 hit_count
                 # 用戶可在 UI 查看聚合次數，避免 Telegram 洗版
                 logger.info(
-                    "alertmanager_converged_telegram_skipped",
+                    "alertmanager_converged_telegram_recurrence_scheduled",
                     approval_id=str(updated_approval.id),
                     hit_count=updated_approval.hit_count,
-                    reason="Converged alert - Telegram already sent for this fingerprint",
+                    reason="Converged alert - scheduling throttled recurrence notice",
                 )
                 background_tasks.add_task(
                     record_alertmanager_event,
@@ -2718,10 +2735,24 @@ async def alertmanager_webhook(
                     labels=dict(alert.labels) if alert.labels else {},
                     annotations=dict(alert.annotations) if alert.annotations else {},
                 )
+                background_tasks.add_task(
+                    notify_converged_alert_recurrence,
+                    source="alertmanager",
+                    fingerprint=fingerprint,
+                    alertname=alertname,
+                    severity=severity,
+                    namespace=namespace,
+                    target_resource=target_resource,
+                    hit_count=updated_approval.hit_count,
+                    incident_id=getattr(updated_approval, "incident_id", None),
+                    approval_id=str(updated_approval.id),
+                    alert_category=alert_category,
+                    notification_type=notification_type,
+                )
 
                 return AlertResponse(
                     success=True,
-                    message=f"🛡️ 告警收斂 (x{updated_approval.hit_count}) - Telegram 已發送，跳過重複通知",
+                    message=f"🛡️ 告警收斂 (x{updated_approval.hit_count}) - 已排程節流再通知",
                     alert_id=alert_id,
                     approval_created=False,
                     approval_id=str(updated_approval.id),

apps/api/src/services/converged_alert_recurrence_notifier.py

@@ -0,0 +1,194 @@
+"""Throttled Telegram notices for converged alert fingerprints."""
+
+import hashlib
+import html
+
+from src.core.config import settings
+from src.core.logging import get_logger
+from src.core.redis_client import get_redis
+from src.services.telegram_gateway import get_telegram_gateway
+
+logger = get_logger("awoooi.converged_alert_recurrence")
+
+CONVERGED_ALERT_RECURRENCE_REDIS_PREFIX = "awoooi:tg:converged_alert_recurrence:"
+CONVERGED_ALERT_RECURRENCE_TTL_SECONDS = 30 * 60
+CONVERGED_ALERT_RECURRENCE_FALLBACK_MILESTONES = frozenset({2, 3, 5, 10, 20, 50, 100})
+
+
+def shorten_alert_text(value: str | None, *, limit: int = 80) -> str:
+    """Keep Telegram recurrence notices readable and HTML-safe."""
+
+    text = " ".join(str(value or "-").split())
+    if len(text) <= limit:
+        return html.escape(text)
+    return html.escape(f"{text[: limit - 3]}...")
+
+
+def is_converged_alert_recurrence_milestone(hit_count: int) -> bool:
+    """Fallback dedupe when Redis is unavailable."""
+
+    if hit_count <= 1:
+        return False
+    return hit_count in CONVERGED_ALERT_RECURRENCE_FALLBACK_MILESTONES or hit_count % 100 == 0
+
+
+def converged_alert_recurrence_key(fingerprint: str) -> str:
+    digest = hashlib.sha256(str(fingerprint or "missing").encode()).hexdigest()[:32]
+    return f"{CONVERGED_ALERT_RECURRENCE_REDIS_PREFIX}{digest}"
+
+
+async def should_notify_converged_alert_recurrence(
+    *,
+    fingerprint: str,
+    hit_count: int,
+) -> bool:
+    """Throttle converged alert notices without making active incidents disappear."""
+
+    if hit_count <= 1:
+        return False
+
+    key = converged_alert_recurrence_key(fingerprint)
+    try:
+        redis = get_redis()
+        acquired = await redis.set(
+            key,
+            str(hit_count),
+            ex=CONVERGED_ALERT_RECURRENCE_TTL_SECONDS,
+            nx=True,
+        )
+        return bool(acquired)
+    except Exception as exc:
+        logger.warning(
+            "converged_alert_recurrence_dedup_unavailable",
+            fingerprint_hash=key.rsplit(":", 1)[-1],
+            hit_count=hit_count,
+            fallback="milestone",
+            error=str(exc),
+        )
+        return is_converged_alert_recurrence_milestone(hit_count)
+
+
+def format_converged_alert_recurrence_message(
+    *,
+    source: str,
+    alertname: str,
+    severity: str,
+    namespace: str,
+    target_resource: str,
+    hit_count: int,
+    incident_id: str | None,
+    approval_id: str | None,
+    alert_category: str = "",
+    notification_type: str = "",
+) -> str:
+    """Build a concise recurrence notice for an already-open alert fingerprint."""
+
+    return "\n".join(
+        [
+            "<b>告警仍在發生</b>",
+            "同一指紋已收斂，系統保留去重，但不再完全靜音。",
+            "",
+            f"來源：<code>{shorten_alert_text(source, limit=40)}</code>",
+            f"告警：<code>{shorten_alert_text(alertname, limit=80)}</code>",
+            f"嚴重度：<code>{shorten_alert_text(severity, limit=24)}</code>",
+            f"目標：<code>{shorten_alert_text(target_resource, limit=80)}</code>",
+            f"命名空間：<code>{shorten_alert_text(namespace, limit=48)}</code>",
+            f"累計次數：<b>{hit_count}</b>",
+            f"事件：<code>{shorten_alert_text(incident_id, limit=48)}</code>",
+            f"簽核：<code>{shorten_alert_text(approval_id, limit=48)}</code>",
+            f"分類：<code>{shorten_alert_text(alert_category or '-', limit=48)}</code>",
+            f"通知型別：<code>{shorten_alert_text(notification_type or '-', limit=48)}</code>",
+            "",
+            "下一步：請查看 AwoooP 事件時間線；這不是新的自動修復授權。",
+        ]
+    )
+
+
+async def notify_converged_alert_recurrence(
+    *,
+    source: str,
+    fingerprint: str,
+    alertname: str,
+    severity: str,
+    namespace: str,
+    target_resource: str,
+    hit_count: int,
+    incident_id: str | None,
+    approval_id: str | None,
+    alert_category: str = "",
+    notification_type: str = "",
+) -> None:
+    """Send a throttled recurrence notice for an already-open alert fingerprint."""
+
+    if not await should_notify_converged_alert_recurrence(
+        fingerprint=fingerprint,
+        hit_count=hit_count,
+    ):
+        logger.info(
+            "converged_alert_recurrence_throttled",
+            source=source,
+            hit_count=hit_count,
+            approval_id=approval_id,
+        )
+        return
+
+    text = format_converged_alert_recurrence_message(
+        source=source,
+        alertname=alertname,
+        severity=severity,
+        namespace=namespace,
+        target_resource=target_resource,
+        hit_count=hit_count,
+        incident_id=incident_id,
+        approval_id=approval_id,
+        alert_category=alert_category,
+        notification_type=notification_type,
+    )
+
+    gateway = get_telegram_gateway()
+    sent_count = 0
+    failures: list[str] = []
+
+    try:
+        await gateway.send_alert_notification(text)
+        sent_count += 1
+    except Exception as exc:
+        failures.append(f"primary:{type(exc).__name__}")
+        logger.warning(
+            "converged_alert_recurrence_primary_failed",
+            source=source,
+            approval_id=approval_id,
+            error=str(exc),
+        )
+
+    private_chat_id = settings.OPENCLAW_TG_CHAT_ID
+    if private_chat_id and private_chat_id != gateway.alert_chat_id:
+        try:
+            await gateway.send_notification(text, chat_id=private_chat_id)
+            sent_count += 1
+        except Exception as exc:
+            failures.append(f"private:{type(exc).__name__}")
+            logger.warning(
+                "converged_alert_recurrence_private_mirror_failed",
+                source=source,
+                approval_id=approval_id,
+                error=str(exc),
+            )
+
+    if sent_count:
+        logger.info(
+            "converged_alert_recurrence_sent",
+            source=source,
+            hit_count=hit_count,
+            approval_id=approval_id,
+            mirrored_to_private=bool(private_chat_id and private_chat_id != gateway.alert_chat_id),
+            sent_count=sent_count,
+        )
+    else:
+        logger.error(
+            "converged_alert_recurrence_failed",
+            source=source,
+            hit_count=hit_count,
+            approval_id=approval_id,
+            failures=failures,
+        )