feat(k8s): API Pod 掛載 repair SSH key (Task 13)

- 06-deployment-api.yaml: volumeMount /etc/repair-ssh + volumes secret defaultMode 0400
- 對應 K8s Secret: awoooi-repair-ssh-key

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

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

@@ -50,6 +50,11 @@ spec:
                 name: awoooi-config
             - secretRef:
                 name: awoooi-secrets
+          # 2026-04-05 Claude Code: Sprint 3 — 掛載 SSH key 供 HostRepairAgent 使用
+          volumeMounts:
+            - name: repair-ssh-key
+              mountPath: /etc/repair-ssh
+              readOnly: true
           resources:
             requests:
               cpu: "200m"
@@ -92,6 +97,12 @@ spec:
                   matchLabels:
                     app: awoooi-api
                 topologyKey: kubernetes.io/hostname
+      # 2026-04-05 Claude Code: Sprint 3 — repair SSH key (defaultMode 0400)
+      volumes:
+        - name: repair-ssh-key
+          secret:
+            secretName: awoooi-repair-ssh-key
+            defaultMode: 0400
 
 ---
 apiVersion: v1