feat(k8s): 新增 core 真应用(前端+Django API+Celery worker)构建与部署

- core/frontend: Vite 多阶段镜像 + nginx 同源反代 /api,/admin,/static(零 CORS)
- core/backend: Django gunicorn 镜像 + entrypoint(自动 migrate/collectstatic)+ WhiteNoise
- k8s/core: api/worker/web Deployment+Service + ingress(airshelf-web.airlabs.art)
- workflow: 追加 core 前后端 build/push,从 core/backend/.env 套生产覆盖生成 env Secret 后部署
- .gitignore 放行 core/backend/.env;.env 白名单加入 airshelf-web 域名
- 含前端 WIP 还原改动

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

k8s/core/worker-deployment.yaml

@@ -0,0 +1,43 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: airshelf-core-worker
+  labels:
+    app: airshelf-core-worker
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: airshelf-core-worker
+  template:
+    metadata:
+      labels:
+        app: airshelf-core-worker
+    spec:
+      imagePullSecrets:
+      - name: cr-pull-secret
+      containers:
+      - name: airshelf-core-worker
+        image: ${CI_REGISTRY_IMAGE}/airshelf-core-api:latest
+        imagePullPolicy: Always
+        # Celery worker connects to the external (Volcano managed) Redis broker
+        # configured via the airshelf-core-env secret. Uses `args` (not `command`)
+        # so the image ENTRYPOINT still runs but skips migrate/collectstatic ($1=celery).
+        args: ["celery", "-A", "airshelf.celery:app", "worker", "-l", "info", "--concurrency", "2"]
+        envFrom:
+        - secretRef:
+            name: airshelf-core-env
+        livenessProbe:
+          exec:
+            command: ["sh", "-c", "celery -A airshelf.celery:app inspect ping"]
+          initialDelaySeconds: 40
+          periodSeconds: 60
+          timeoutSeconds: 15
+          failureThreshold: 3
+        resources:
+          requests:
+            memory: "256Mi"
+            cpu: "100m"
+          limits:
+            memory: "768Mi"
+            cpu: "1000m"