[eunjun-strato]

Summary

• Replace Docker Hub-to-Nexus image imports with Skopeo bundled in the AM image. Preserve the existing Import & Create workflow without mounting the Docker socket, changing the host Docker Engine configuration, or modifying mc-admin-cli.
• Preserve source digests and multi-platform manifests. Create temporary authentication files with restricted permissions and remove them after use. Existing Nexus credentials and Registry read/write permissions are still required.
• Fix image/tag duplicate detection and prevent Catalog registration after an image transfer fails. Optional Registry endpoint overrides are not required in the default internal-network configuration.
• Include the deployment failure messages, detail logs, and modal lifecycle improvements from fix: 배포 실패 로그·상세 팝업 및 K8s 차트 버전 개선 #216, Kubernetes memory quantity handling, and bundled Helm chart version 0.1.1 updates.
• Allow uninstalling failed applications and fix missing logs when deleting Catalogs with nullable relationships.
• Build and bundle the latest frontend in CI/CD images.

Validation

The following results are carried over from #217; tests were not rerun for this English-only PR replacement.

• Gradle: 828 tests, 0 failures, 0 errors, and 1 conditional skip.
• Frontend build and type checks passed; verified 26 failed-uninstall cases and 64 built-in chart form cases.
• Imported ghost:bookworm through the UI and confirmed the same image/tag in Repository. Source and destination SHA256 digests matched; independently verified 6 child manifests and 40 blobs.
• Additional API checks: copied busybox:1.37.0 with matching digests, rejected nonexistent tags and invalid image names, and checked duplicate detection across different tags of the same image.
• Replaced only the AM image. The other 43 service containers and host Docker Registry configuration remained unchanged. Full-content hashes of the existing 421 daily archive records were preserved, and collection continued.
• Removed test Catalogs, Packages, Repositories, and copied images. No VMs or clusters were created, and existing applications were not redeployed.

Scope and limitations

• The new Registry-copy implementation covers the existing public Docker Hub workflow; it does not add source authentication for private images.
• HTTP destinations remain supported for compatibility but are not encrypted. Certificate verification remains enabled for Docker Hub sources and HTTPS destinations. Copying all platforms may transfer more data than copying a single platform.
• Sensitive local handover documents and data-generation/recovery scripts are excluded.
• This PR replaces fix: Docker 엔진 없는 Nexus 이미지 저장 및 실패 배포 관리 개선 #217 with the same commits and an English title and description. It also includes the changes previously proposed in fix: 배포 실패 로그·상세 팝업 및 K8s 차트 버전 개선 #216.