ci: 添加 Gitea Actions 部署流水线 + K3s 清单

对齐 jimeng-clone 的流水线结构(master→prod / dev→dev),适配 AirShelf 纯静态形态:
- 电商AI平台/Dockerfile · 纯 nginx,无 build 阶段
- 电商AI平台/nginx.conf · 多入口 try_files,不 fallback 到 index.html
- k8s/ · web-deployment + ingress + cert-issuer + redirect middleware
- .gitea/workflows/deploy.yaml · build/push 重试 3 次,deploy 重试 5 次,失败上报日志中心
- prod 域名 airshelf.airlabs.art / dev 域名 airshelf.test.airlabs.art

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

k8s/ingress.yaml

@@ -0,0 +1,24 @@
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: airshelf-ingress
+  annotations:
+    kubernetes.io/ingress.class: "traefik"
+    cert-manager.io/cluster-issuer: "letsencrypt-prod"
+    traefik.ingress.kubernetes.io/router.middlewares: "default-redirect-https@kubernetescrd"
+spec:
+  tls:
+  - hosts:
+    - airshelf.airlabs.art
+    secretName: airshelf-tls
+  rules:
+  - host: airshelf.airlabs.art
+    http:
+      paths:
+      - path: /
+        pathType: Prefix
+        backend:
+          service:
+            name: airshelf-web
+            port:
+              number: 80