feat: Add CDS Containers with GHCR build workflow

[mmou-nv]

🐳 Add CDS Container Images

This PR adds CDS container images to the dsx-github-actions repository with GitHub Container Registry (GHCR) support.

📦 Container Images

1. cds-tools - Comprehensive tooling container

   • Bazel (6.5.0 & 8.4.0), kubectl, helm, terraform, terragrunt
   • NGC CLI, Docker CLI, regctl
   • Node.js 24, Python 3, uv

2. cds-go-dev-1.24-alpine - Go development (Alpine)

   • Minimal size (~50MB)
   • Go 1.24.3 + golangci-lint + goimports + delve

3. cds-go-dev-1.24-debian - Go development (Debian)

   • Better compatibility (~300MB)
   • For CGO-enabled packages

4. cds-grafana-backup-tool - Grafana backup utility

✨ Features

• Version Management: Uses VERSION.md file (currently 0.0.1)
• GHCR Integration: Pushes to ghcr.io/nvidia/dsx-github-actions/cds-*
• Path-Filtered Pipeline: Only triggers on cds-containers/ changes
• Automated Testing: Tests built images before completion
• Documentation: Comprehensive README with usage examples

🔧 Usage Example

jobs:
  build:
    runs-on: ubuntu-latest
    permissions:
      packages: read
    
    container:
      image: ghcr.io/nvidia/dsx-github-actions/cds-tools:0.0.1
      credentials:
        username: ${{ github.actor }}
        password: ${{ secrets.GITHUB_TOKEN }}
    
    steps:
      - uses: actions/checkout@v4
      - run: bazel build //...

📝 Key Differences from GitLab Version

• ❌ Removed nvault (requires internal URM access)
• ❌ Removed cds-cli (requires internal GitLab access)
• ✅ Version from VERSION.md instead of Git tags
• ✅ Path-filtered pipeline for efficiency
• ✅ GHCR instead of GitLab Container Registry

🧪 Testing

Tested in test-dsx-ci repo:

• ✅ All 4 images build successfully
• ✅ Images push to GHCR as private packages
• ✅ Test jobs can consume built images
• ✅ Version tagging works correctly

📂 Files Added

• cds-containers/ - Container definitions and Dockerfiles
• .github/workflows/build-cds-containers.yml - Build pipeline
• cds-containers/VERSION.md - Version file (0.0.1)
• cds-containers/README.md - Documentation

[github-actions]

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[mmou-nv]

I have read the DCO Document and I hereby sign the DCO

[mmou-nv]

recheck