fix(ci): E2E kubectl 診斷改為非阻塞 (graceful fallback)

- 移除對 KUBECONFIG secret 的依賴
- kubectl 無法連線時 graceful 跳過
- 保留 API health check 作為主要驗證

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

.github/workflows/daily-e2e-health.yaml

@@ -70,12 +70,16 @@ jobs:
         run: uv sync
 
       - name: Check K8s Status
-        env:
-          KUBECONFIG: ${{ secrets.KUBECONFIG }}
         run: |
           echo "🔍 檢查 K8s 服務狀態..."
-          echo "$KUBECONFIG" | base64 -d > /tmp/kubeconfig
-          export KUBECONFIG=/tmp/kubeconfig
+
+          # 使用 runner 本地的 kubectl 配置 (與 CD 一致)
+          # 如果沒有配置，跳過 K8s 診斷
+          if ! kubectl cluster-info > /dev/null 2>&1; then
+            echo "⚠️ kubectl 無法連線叢集，跳過 K8s 診斷"
+            echo "   (Runner 可能沒有 kubectl 存取權限)"
+            exit 0
+          fi
 
           echo "📦 Pod 狀態:"
           kubectl get pods -n awoooi-prod -l app=awoooi-api -o wide || echo "⚠️ kubectl 失敗"
@@ -88,8 +92,6 @@ jobs:
           echo "📋 Endpoints:"
           kubectl get endpoints -n awoooi-prod awoooi-api || echo "⚠️ kubectl 失敗"
 
-          rm -f /tmp/kubeconfig
-
       - name: Check API Health
         run: |
           API_URL="${{ github.event.inputs.api_url || env.DEFAULT_API_URL }}"