fix(cd): 處理 K8s selector immutability 問題

問題: kustomize labels 配置變更導致 selector 不匹配
修復: 偵測到 "field is immutable" 錯誤時自動刪除重建 Deployment

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

.github/workflows/cd.yaml

@@ -281,7 +281,19 @@ jobs:
             echo "⏭️ 跳過 Web image 更新 (build skipped)"
           fi
 
-          kubectl apply -k .
+          # 2026-03-26: 處理 selector immutability 問題
+          # 如果 apply 失敗 (通常是 selector 變更)，先刪除再重建
+          if ! kubectl apply -k . 2>&1 | tee /tmp/apply.log; then
+            if grep -q "field is immutable" /tmp/apply.log; then
+              echo "⚠️ 偵測到 selector 不可變錯誤，執行強制重建..."
+              kubectl delete deployment awoooi-api awoooi-web awoooi-worker -n awoooi-prod --ignore-not-found
+              sleep 5
+              kubectl apply -k .
+            else
+              echo "❌ 部署失敗 (非 selector 問題)"
+              exit 1
+            fi
+          fi
 
       # 2026-03-26: CoreDNS GitOps 同步 (ADR-026)
       - name: Sync CoreDNS Config