ci(deploy): support pulling published docker images

env-example/.deploy.env.example

@@ -0,0 +1,19 @@
+# Server-only deploy configuration.
+# Copy this file to .deploy.env on the deployment server when you want the
+# post-receive hook to pull CI-built images instead of building locally.
+
+# build: build Docker image on the deployment server.
+# pull: pull Docker image from registry and restart the container.
+COZSWEET_DEPLOY_IMAGE_SOURCE=pull
+
+# Full image repository without tag.
+# Example:
+# COZSWEET_REGISTRY_IMAGE=registry.example.com/cozsweet/cozsweet-web
+COZSWEET_REGISTRY_IMAGE=
+
+# Optional. Defaults to <deploy_env>-<short_sha>, for example:
+# - test-abc1234 on test branch
+# - prod-abc1234 on main branch
+#
+# You may set this to test-latest or prod-latest for latest-tag deploys.
+# COZSWEET_REMOTE_IMAGE_TAG=