chore: add OCI standard labels to Dockerfile

[Erwan-loot]

Context

Add OCI (Open Container Initiative) standard labels to the Dockerfile for better image metadata and container registry compatibility.

Type

Improvement — metadata only, no functional changes.

Labels Added

Label	Value	Source
org.opencontainers.image.title	mazanoke	Static
org.opencontainers.image.description	A self-hosted local image optimizer that runs in your browser	Static
org.opencontainers.image.url	https://github.com/civilblur/mazanoke	Static
org.opencontainers.image.source	https://github.com/civilblur/mazanoke	Static
org.opencontainers.image.vendor	civilblur	Static
org.opencontainers.image.licenses	GPL-3.0-only	Static
org.opencontainers.image.version	${VERSION}	Build arg (optional)
org.opencontainers.image.revision	${REVISION}	Build arg (optional)
org.opencontainers.image.created	${CREATED}	Build arg (optional)

The three dynamic labels (version, revision, created) use optional build args — the image builds fine without them, they'll simply be empty. When you add CI/CD for automated builds, you can wire them up like so:

docker build \
  --build-arg VERSION=1.0.0 \
  --build-arg REVISION=$(git rev-parse HEAD) \
  --build-arg CREATED=$(date -u +"%Y-%m-%dT%H:%M:%SZ") \
  -t ghcr.io/civilblur/mazanoke:1.0.0 .

Benefits

• Registry UI: GHCR displays title, description, license, and source link in its web interface once these labels are present
• Dependency bot changelogs: Tools like Renovate and Dependabot use org.opencontainers.image.source to locate and display changelogs in update PRs — users who self-host mazanoke via Docker will see release notes when updates land
• Image provenance: revision and created allow precise auditing of which source commit produced an image
• Standardization: follows OCI best practices for container image metadata

Changes

• Dockerfile: added ARG VERSION, ARG REVISION, ARG CREATED and a LABEL block in the final nginx:alpine stage, placed after the last COPY and before EXPOSE

References

• OCI Image Spec - Annotations
• Renovate Docker datasource
• Docker - Manage tags and labels

[civilblur]

Thanks for sharing this, will read up on OCI before taking any action.