Decommission Jekyll site (PR3 — DO NOT MERGE until querygym.com is on CF Pages)

[radinhamidi]

⚠️ Draft / Do not merge yet. Merging this PR removes the Jekyll site that currently serves `querygym.com` via GitHub Pages. Don't merge until the Cloudflare Pages project for the new Astro marketing site is live and `querygym.com` resolves to it. Otherwise the domain goes down between merge and CF DNS propagation.

Summary

PR3 of the website rollout. Removes the Jekyll setup that was replaced by the Astro app under `web/site/` (PR #7) deployed to Cloudflare Pages.

Deletions

Path	Why
`_config.yml`	Jekyll config
`_layouts/default.html`	Jekyll layout (replaced by `@qg/shared/components/Header.astro` + `Footer.astro`)
`index.md`	Root homepage (was `{% include_relative README.md %}`)
`Gemfile`	Jekyll/Ruby deps
`docs/leaderboard.html`	Replaced by `leaderboard.querygym.com`
`.github/workflows/pages.yml`	Jekyll deploy workflow (no longer the deploy target)

Updates

• `README.md` — top-level link bar now points at the new domains (querygym.com / leaderboard.querygym.com / dashboard.querygym.com)
• `docs/index.md` — MkDocs leaderboard link uses the subdomain

Preserved

• `docs/querygym-logo.{png,gif}` — used by MkDocs (`querygym.readthedocs.io`)
• All other `docs/` markdown — MkDocs sources, untouched
• Workflows: `publish.yml`, `docker.yml`, `reproducibility-check.yml`, `leaderboard-build.yml`, `site-build.yml`

Python package isolation — verified

Check	Result
`python -m build`	Clean
sdist leak grep (incl. `_config`, `_layouts`, `Gemfile`, `leaderboard.html`, `pages.yml`)	no leak
Wheel	36 files, all under `querygym/` (unchanged)
pip install	byte-identical

Operator follow-ups (not in this PR)

1. Cloudflare Pages: create `querygym-site` project pointing at `web/site/` (root_dir), custom domain `querygym.com` and `www.querygym.com` redirect.
2. Cloudflare Bulk Redirects on the `querygym.com` zone:
   • `/leaderboard*` → `https://leaderboard.querygym.com/\` (301)
   • `/QueryGym/*` → `https://querygym.com/$1\` (301)
3. GitHub Settings → Pages: source = None.
4. After merge: optionally bump version on PyPI / cut a release.

Test plan

• `pnpm -F @qg/leaderboard build` → 37 pages.
• `pnpm -F @qg/site build` → 6 pages.
• `python -m pytest reproducibility/tests --no-cov` → 19 passed.
• `python -m build` → wheel + sdist clean.
• CI on this PR runs the remaining workflows (no Pages workflow exists anymore — that's the point).
• `querygym.com` is live on CF Pages preview before merging.
• After merge: `/leaderboard` redirect verified.

🤖 Generated with Claude Code