feat: Container release via Docker + GitHub Actions

[pmcfadin]

Summary

• Add multi-stage Dockerfile (node:22-alpine build → nginx:alpine serve, ~45-55 MB final image)
• Add nginx config template with SPA routing, API reverse proxy (${API_BACKEND_URL}), cache headers (immutable for hashed assets, no-cache for index.html), and gzip
• Add GitHub Actions workflow that builds and pushes to ghcr.io/killrvideo/killrvideo-react-frontend on push to main (tags: latest + sha-<short>) and semver tags (tags: 1.2.3, 1.2, 1)
• Add .dockerignore to keep build context small

Closes #48

Usage

# Run locally
docker build -t killrvideo-frontend .
docker run --rm -p 8080:8080 -e API_BACKEND_URL=http://host.docker.internal:8443 killrvideo-frontend

# Cut a release
git tag v1.0.0 && git push origin v1.0.0

# Pull from registry
docker pull ghcr.io/killrvideo/killrvideo-react-frontend:latest

Test plan

• Docker build completes successfully (will be validated by GHA workflow on merge)
• SPA routing works — non-root paths serve index.html
• /assets/* returns Cache-Control: public, immutable
• / returns Cache-Control: no-cache
• API requests to /api/ are proxied to API_BACKEND_URL
• Final image is ~45-55 MB
• GitHub Actions workflow runs on push to main and publishes to ghcr.io

Note

First-time ghcr.io setup: after the workflow's first run, an org admin needs to set package visibility in GitHub package settings.

🤖 Generated with Claude Code

[aar0np]

Nice! Glad to see a production-level Docker container.