feat(cli): deploy agent engine to Artifact Registry instead of GCR (Agent Engine Deployment Artifact registry fix part 2)

[AmaadMartin]

Please ensure you have read the contribution guide https://google.github.io/adk-docs/contributing-guide/ before creating a pull request.

Link to Issue or Description of Change

1. Link to an existing issue (if applicable):

• Closes: #none
• Related: #none

2. Or, if no issue exists, describe the change:

Problem:

1. The ADK CLI was using the deprecated gcr.io container registry for Reasoning Engine builds.
2. If developers do not have a Docker repository set up in Artifact Registry, the deployment failed late and cryptically.
3. In corporate VPC Service Control (VPC-SC) perimeters, the default Google Cloud Build logs bucket is blocked, causing gcloud builds submit to return exit code 1 even when the build completes successfully.

Solution:

1. Switched container packaging repository to Google Cloud Artifact Registry (${region}-docker.pkg.dev/${project}/${repository}/...).
2. Added validation requiring the --repository option, failing early with explicit regional gcloud creation instructions if omitted.
3. Redirected Cloud Build logs to the local project-owned staging bucket (gs://${project}_cloudbuild/logs) via the --gcs-log-dir flag to bypass VPC-SC restrictions.

Testing Plan

Unit Tests:

• I have added or updated unit tests for my change.
• All unit tests pass locally.

Summary of passed test results:

✓ |unit:dev| dev/test/cli/cli_deploy_agent_engine_test.ts (13 tests) 69ms
✓ deployToAgentEngine > should deploy successfully with explicit options 18ms
✓ deployToAgentEngine > should deploy successfully with all optional parameters 3ms
✓ deployToAgentEngine > should resolve default project and region from gcloud if not provided 4ms
✓ deployToAgentEngine > should deploy successfully with custom repository name 4ms
✓ deployToAgentEngine > should throw error if region resolution fails (unset) 4ms
✓ deployToAgentEngine > should deploy successfully when agentPath is a file 3ms
✓ deployToAgentEngine > should deploy successfully without explicit displayName 2ms
✓ deployToAgentEngine > should throw error if project resolution fails (unset) 2ms
✓ deployToAgentEngine > should clean up existing temp folder before deploying 2ms
✓ deployToAgentEngine > should throw error if required npm packages are missing in package.json 4ms
✓ deployToAgentEngine > should handle spawn failures during build 2ms
✓ deployToAgentEngine > should throw error if Reasoning Engine creation operation times out 9ms

Files tested:

• dev/test/cli/cli_deploy_agent_engine_test.ts

Manual End-to-End (E2E) Tests:

Successfully ran:

ADK_DEV_MODE=true node dev/dist/esm/cli_entrypoint.js deploy agent_engine /tmp/observability-e2e-run/real_agent.ts
--project amaadmartin-claw-15058
--region us-central1
--repository agent-engine-repo
--temp_folder /tmp/observability-e2e-run/temp-adk-deploy
--port 8080

Which built, pushed, created the Reasoning Engine, and responded to querying successfully under VPC-SC.

Checklist

• I have read the CONTRIBUTING.md https://github.com/google/adk-js/blob/main/CONTRIBUTING.md document.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.
• I have manually tested my changes end-to-end.

Additional context

This PR is stacked on top of #440.