fix(k8s): add prod workload topology spread

k8s/awoooi-prod/05-deployment-web.yaml

@@ -33,6 +33,16 @@ spec:
         system: awoooi
         environment: prod
     spec:
+      # 2026-06-13 Codex: 明確偏好跨 120 / 121 分散，但不在單節點維護時卡死 rollout。
+      topologySpreadConstraints:
+        - maxSkew: 1
+          topologyKey: kubernetes.io/hostname
+          whenUnsatisfiable: ScheduleAnyway
+          labelSelector:
+            matchLabels:
+              app: awoooi-web
+              environment: prod
+              system: awoooi
       containers:
         - name: web
           # 映像標籤由 CI/CD 動態注入 (格式: {sha}-{run_id})

k8s/awoooi-prod/06-deployment-api.yaml

@@ -35,6 +35,16 @@ spec:
         system: awoooi
         environment: prod
     spec:
+      # 2026-06-13 Codex: 明確偏好跨 120 / 121 分散，但不在單節點維護時卡死 rollout。
+      topologySpreadConstraints:
+        - maxSkew: 1
+          topologyKey: kubernetes.io/hostname
+          whenUnsatisfiable: ScheduleAnyway
+          labelSelector:
+            matchLabels:
+              app: awoooi-api
+              environment: prod
+              system: awoooi
       # Phase 7: 使用 RBAC ServiceAccount (最小權限)
       serviceAccountName: awoooi-executor
       automountServiceAccountToken: true

k8s/awoooi-prod/08-deployment-worker.yaml

@@ -41,6 +41,16 @@ spec:
         environment: prod
         component: signal-processor
     spec:
+      # 2026-06-13 Codex: Worker 目前 min=1，但 HPA 擴到多副本時優先跨節點分散。
+      topologySpreadConstraints:
+        - maxSkew: 1
+          topologyKey: kubernetes.io/hostname
+          whenUnsatisfiable: ScheduleAnyway
+          labelSelector:
+            matchLabels:
+              app: awoooi-worker
+              environment: prod
+              system: awoooi
       # ADR-038/039: Graceful Shutdown (Worker 需要 75 秒完成清理)
       serviceAccountName: awoooi-executor
       automountServiceAccountToken: true