build(dockerfile): missing OCI labels (org.opencontainers.image.source, .licenses, .version)

gh issue create --title "build(dockerfile): missing OCI labels (org.opencontainers.image.source, .licenses, .version)" --label "build,audit,priority:low" --body "## Finding

Dockerfile does not set OCI image labels (org.opencontainers.image.source, org.opencontainers.image.licenses, org.opencontainers.image.version, org.opencontainers.image.revision). Container registries use these to render metadata, and `docker inspect` users see them as a contract.

## Affected code

- Dockerfile — LABEL instructions (missing)

## Reproduction

1. `docker inspect | jq '.[0].Config.Labels'`.
2. Observe no OCI labels.

## Suggested fix

Add LABEL statements:

LABEL org.opencontainers.image.source=\"https://github.com/airvzxf/ftp-deployment-action\" \\
org.opencontainers.image.licenses=\"AGPL-3.0\" \\
org.opencontainers.image.version=\"\${VERSION}\"

Pass VERSION via --build-arg. Or use the GitHub Actions `docker/metadata-action` to set them at build time.

## Source

F2 audit 2026-09-03 (Dockerfile/Makefile audit). Reporter: subagent-pekodbj7.

## Related

- Part of EPIC #[epic-number]
- Closes: #NONE (no existing issue)"

Start in Dockerfile and review the existing image build instructions plus any repository build invocation that supplies VERSION. Build the image, then run the reported docker inspect command to check its labels. Done means the requested OCI source, license, version, and revision metadata are visible in the image configuration.

Written by the indexing model from the issue text.