feat: add direct PostgreSQL and ACK deployment support

deploy/ack/secrets.example.yaml

@@ -0,0 +1,36 @@
+# Example only. Replace every placeholder and keep the populated file out of Git.
+apiVersion: v1
+kind: Secret
+metadata:
+  name: zhinian-web-db
+  namespace: zhinian
+type: Opaque
+stringData:
+  DATABASE_URL: postgresql://APP_USER:APP_PASSWORD@RDS_INTERNAL_HOST:5432/APP_DATABASE
+---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: zhinian-migration-db
+  namespace: zhinian
+type: Opaque
+stringData:
+  DATABASE_URL: postgresql://MIGRATION_USER:MIGRATION_PASSWORD@RDS_INTERNAL_HOST:5432/APP_DATABASE
+---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: zhinian-worker-auth
+  namespace: zhinian
+type: Opaque
+stringData:
+  ZHINIAN_INTERNAL_WORKER_TOKEN: REPLACE_WITH_A_LONG_RANDOM_VALUE
+---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: zhinian-web-auth
+  namespace: zhinian
+type: Opaque
+stringData:
+  ZHINIAN_AUTH_SESSION_SECRET: REPLACE_WITH_A_DIFFERENT_LONG_RANDOM_VALUE