feat(api): Phase 21.2 K3s Status Telegram Report (ADR-041)

- 新增 K3sStatusMessage dataclass (telegram_gateway.py)
- 新增 K3sMonitorService (Prometheus 數據收集)
- 新增 CronJob (每日 09:00 台北)
- 新增 API 端點 (/stats/k3s/status, /stats/k3s/report)

Phase 21 定期報告機制 (統帥已批准)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/api/src/api/v1/stats.py

@@ -25,6 +25,7 @@ from fastapi import APIRouter, Depends, Query
 from pydantic import BaseModel, Field
 
 from src.services.stats_service import StatsService, get_stats_service
+from src.services.k3s_monitor_service import K3sMonitorService, get_k3s_monitor_service
 
 router = APIRouter(prefix="/stats", tags=["Statistics"])
 
@@ -34,6 +35,7 @@ router = APIRouter(prefix="/stats", tags=["Statistics"])
 # =============================================================================
 
 StatsServiceDep = Annotated[StatsService, Depends(get_stats_service)]
+K3sMonitorDep = Annotated[K3sMonitorService, Depends(get_k3s_monitor_service)]
 
 
 # =============================================================================
@@ -265,3 +267,72 @@ async def get_feedback_summary(
     """
     result = await service.get_feedback_summary(days)
     return FeedbackSummary(**result)
+
+
+# =============================================================================
+# K3s Status Report (Phase 21.2)
+# =============================================================================
+
+
+class K3sStatusResponse(BaseModel):
+    """K3s 叢集狀態回應"""
+
+    report_date: str = Field(description="報告日期時間")
+    node_total: int = Field(description="節點總數")
+    node_ready: int = Field(description="就緒節點數")
+    pod_running: int = Field(description="執行中 Pod 數")
+    pod_pending: int = Field(description="等待中 Pod 數")
+    pod_failed: int = Field(description="失敗 Pod 數")
+    hpa_api: str = Field(description="API HPA 副本數")
+    hpa_web: str = Field(description="Web HPA 副本數")
+    hpa_worker: str = Field(description="Worker HPA 副本數")
+    alert_count_48h: int = Field(description="48h 內告警數")
+    pod_restart_48h: int = Field(description="48h 內 Pod 重啟數")
+
+
+@router.get(
+    "/k3s/status",
+    response_model=K3sStatusResponse,
+    summary="K3s 叢集狀態",
+)
+async def get_k3s_status(
+    monitor: K3sMonitorDep = None,
+) -> K3sStatusResponse:
+    """
+    取得 K3s 叢集當前狀態
+
+    數據來源: Prometheus (kube-state-metrics)
+    """
+    status = await monitor.collect_cluster_status()
+    return K3sStatusResponse(
+        report_date=status.report_date,
+        node_total=status.node_total,
+        node_ready=status.node_ready,
+        pod_running=status.pod_running,
+        pod_pending=status.pod_pending,
+        pod_failed=status.pod_failed,
+        hpa_api=status.hpa_api_replicas,
+        hpa_web=status.hpa_web_replicas,
+        hpa_worker=status.hpa_worker_replicas,
+        alert_count_48h=status.alert_count_48h,
+        pod_restart_48h=status.pod_restart_48h,
+    )
+
+
+@router.post(
+    "/k3s/report",
+    summary="觸發 K3s 報告",
+)
+async def trigger_k3s_report(
+    monitor: K3sMonitorDep = None,
+) -> dict:
+    """
+    手動觸發 K3s 狀態報告發送到 Telegram
+
+    Phase 21.2: 定期報告機制
+    """
+    success = await monitor.send_daily_report()
+    return {
+        "success": success,
+        "message": "報告已發送" if success else "報告發送失敗",
+    }

docs/LOGBOOK.md

@@ -5,12 +5,12 @@
 
 ---
 
-## 📍 當前狀態 (2026-03-31 02:15 台北)
+## 📍 當前狀態 (2026-03-31 02:30 台北)
 
 | 項目 | 狀態 |
 |------|------|
-| **Phase 21.1 Daily E2E** | ✅ **已完成** (每日 00:00 台北自動執行) |
-| **Phase 21.2 K3s Report** | 📋 **待實施** (2h) |
+| **Phase 21.1 Daily E2E** | ✅ **已完成** (每日 00:00 台北) |
+| **Phase 21.2 K3s Report** | ✅ **已完成** (每日 09:00 台北) |
 | **Phase 21.3 Weekly Report** | 📋 **待實施** (2h) |
 | **#15 SSE + 樂觀更新** | ✅ **完成** (`8c8664c`) |
 | **#16 DOM Bypass** | ✅ **完成** (`0b87018`) |