feat: rewrite release & congrats workflows; add docs image

[himanshu231204]

feat: rewrite release & congrats workflows; add docs image

Changes

• .github/workflows/release.yml — rewritten release pipeline:
  • Build with python -m build + verify with twine check (replaces uv build).
  • Trigger on release: [published] and v* tag pushes.
  • Split into publish (build + PyPI trusted publishing via OIDC) and
    release-artifacts (uploads wheel/sdist to the GitHub Release via
    softprops/action-gh-release with contents: write).
  • Note: this drops the in-workflow version-consistency check and the
    ruff/mypy/bandit/pytest quality gates that the prior version ran.
• .github/workflows/congrats.yml — expanded into a structured
  actions/github-script implementation with first-contribution detection
  and structured logging.
• docs/images/modeldock.png — added project image.

Review note

This changes release behavior vs. the uv-based flow that published 0.1.0.
Please confirm the removed quality gates / version check are intentional
before merging, since they affect all future releases.

[github-actions]

🎉 Congratulations @himanshu231204!

Your pull request has been successfully merged into main. 🚀

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We truly appreciate your contribution and hope to see you back with more amazing PRs!

Happy Open Sourcing! ❤️