[ADK CLI] Failed deployment to Agent Engine due to deprecated gcr.io registry & unhandled API errors

[cstanger]

Description

When running npx adk deploy agent_engine <agent_path>, the deployment fails on Vertex AI Reasoning Engine because the ADK CLI tool builds and pushes container images using the deprecated/incompatible gcr.io registry format, whereas the Reasoning Engine service strictly requires Artifact Registry (pkg.dev) images.

---

1. Deprecated gcr.io Registry Issue

The CLI hardcodes gcr.io registry when building and tagging images:
const imageTag = \gcr.io/${options.project}/agent-engine-${appName}:latest`;`

Proposed Fix

The container registry path should be updated to use the Artifact Registry path template, dynamically using the target region (e.g. europe-west3, us-central1, etc.):

const repository = options.repository || "agent-engine-repo"; // Suggested configurable repository
const imageTag = `${options.region}-docker.pkg.dev/${options.project}/${repository}/agent-engine-${appName}:latest`;

---