Reintroduce Quickstart Image

[polyzos]

Purpose

Linked issue: close #3161

Reintroduce the prebuilt apache/fluss-quickstart-flink image into the quickstart flow so the main Flink quickstart works out of the box again, while keeping the lakehouse guides usable with the same image.

Brief change log

• restore the docker/quickstart-flink helper assets, including the Dockerfile, prepare script, SQL client bootstrap script, and README
• keep the base Fluss quickstart dependencies in FLINK_HOME/lib, and package Paimon/Iceberg-specific Flink dependencies in separate image directories that are activated by init scripts when needed
• update the Flink, lakehouse, security, and observability quickstart docs to use apache/fluss-quickstart-flink:$FLUSS_QUICKSTART_FLINK_DOCKER_VERSION$
• preload the demo faker source tables through the quickstart SQL client bootstrap file so users do not need to create them manually in the docs
• align bundled quickstart dependencies with the current lakehouse runtime expectations, including Paimon 1.3.1, paimon-s3, iceberg-aws, iceberg-aws-bundle, postgresql, and hadoop-apache
• keep the Fluss server-side plugins documented as explicit downloads/mounts where they are still required outside the quickstart image

Generative AI disclosure: Yes (OpenAI Codex GPT-5)

Tests

• Not run in CI
• Local quickstart image and doc flow were iterated manually while fixing missing dependency and SQL client bootstrap issues

API and Format

No API or storage format changes intended.

Documentation

Yes. This PR updates the quickstart image assets and the related documentation pages.

[polyzos]

@luoyuxia PTAL

[Copilot]

Pull request overview

This PR reintroduces and operationalizes a pre-bundled Flink quickstart Docker image (apache/fluss-quickstart-flink) and updates the website/docs to reference it via a version placeholder, with CI support to publish images for main and release tags.

Changes:

• Add a new quickstartFlinkDockerVersion field to website version metadata and expose it via the remark version-replacement plugin.
• Update quickstart/observability/security docs to reference the new quickstart image tag placeholder.
• Introduce a docker/quickstart-flink Dockerfile and a GitHub Actions workflow to build/push apache/fluss and apache/fluss-quickstart-flink.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
website/src/plugins/remark-version-replace/index.js	Adds $FLUSS_QUICKSTART_FLINK_DOCKER_VERSION$ replacement for docs.
website/fluss-versions.json	Updates docker versioning for next and adds quickstart image version metadata.
website/docs/quickstart/security.md	Switches Flink image references to the quickstart image placeholder and adjusts SQL client invocation.
website/docs/quickstart/flink.md	Simplifies the Flink quickstart by using the pre-bundled quickstart image.
website/docs/maintenance/observability/quickstart.md	Switches Flink image references to the quickstart image placeholder.
website/community/how-to-release/creating-a-fluss-release.mdx	Updates release steps to reflect CI-built apache/fluss and manual RC quickstart image build.
docker/quickstart-flink/Dockerfile	New Dockerfile to build the pre-bundled Flink quickstart image.
.github/workflows/docker.yaml	New workflow to build/push Docker images on main and v* tags (skipping RC quickstart builds).

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[luoyuxia]

@polyzos Thanks for the pr. I left minor comments. PTAL

[luoyuxia]

@polyzos Hi, I append a commit improve the quickstart build process, and as #2683 (comment), use separate directories to handle different lake format.
PTAL