infra: create frontend Dockerfile for Next.js application

[snowrugar-beep]

Problem Statement

docker/frontend.Dockerfile is referenced in documentation but does not exist. The Next.js frontend application has no container definition for deployment.

Evidence

• Project tree shows docker/ directory exists but all files are missing
• Frontend has Next.js 15 with Turbopack for dev
• Frontend CI (frontend-build.yml) builds but does not produce a Docker image

Impact

Frontend cannot be containerized for deployment to Kubernetes or ECS.

Proposed Solution

Create a Dockerfile at docker/frontend.Dockerfile with:

• deps stage: install node_modules
• build stage: run next build
• production stage: use standalone output mode

Technical Requirements

• Must use Node.js 20 as base
• Must enable output: 'standalone' in next.config.ts for minimal production image
• Must copy only standalone output to production stage
• Must include proper caching for next.js build artifacts

Acceptance Criteria

1. Docker build succeeds
2. Production image is <100MB
3. Container starts and serves the Next.js app on port 3000
4. Standalone output mode is enabled
5. Health check configured

File Inventory

• docker/frontend.Dockerfile (new)

Dependencies

None.

Testing Strategy

• Build image and verify it starts
• Verify all routes render correctly

Security Considerations

• Non-root user in production
• Minimal image size
• Remove build-time dependencies and source maps in production

Definition of Done

• Dockerfile created
• Production image minimal
• Non-root user
• Health check configured

[Moonwalker-rgb]

Hi Maintainer,

I’d love to work on this issue. I’ve reviewed the requirements and believe I can implement the solution according to the project’s guidelines and best practices.

If the issue is available, I’d be happy to take ownership and submit a PR for review.

Thank you for your consideration

[grantfox-oss]

🦊 GrantFox — @Moonwalker-rgb has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #7)
2. Your PR will be reviewed by the VertexChainLabs maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign campaign!

@Moonwalker-rgb's PR #87 was approved and merged by @snowrugar-beep.

🏆 @Moonwalker-rgb: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (261 total points). Track your full progress on GrantFox.

👏 Great work, @Moonwalker-rgb! Keep contributing to VertexChainLabs.