Publish sql.html to GitHub Pages at docs.altinity.com/altinity-sql-browser/

[BorisTyshkevich]

Summary

• Mirrors the built sql.html + a demo docs/config.json (Antalya/github.demo clusters: 2 Google SSO + 2 demo/demo saved connections) onto docs/, so https://docs.altinity.com/altinity-sql-browser/sql.html loads the real app without any ClickHouse-served deployment. GitHub Pages already serves this repo's main branch /docs at that domain.
• Backfills docs/sql.html from the current v0.6.4 release so the page is live as soon as this merges; release.yml now republishes it (last step, after the Helm push) on every future tagged release.
• Fixes loadConfigDoc (src/net/oauth-config.ts) to resolve config.json from the containing directory when basePath is a static filename (e.g. sql.html) rather than a route (e.g. /sql) — the previous code appended /config.json straight onto the URL, which only happened to work because the ClickHouse route has no file extension. Verified live in a headless browser against a static file server at a nested .../sql.html path: config loads and all 4 saved connections render.
• Light doc reconciliation: CHANGELOG.md [Unreleased] entry, and a short note in docs/ASSET-DISTRIBUTION.md clarifying this GitHub Pages mirror is a separate, unauthenticated demo channel from the cluster-serving problem that doc covers.

Manual follow-up (outside this PR)

The "Google SSO" login buttons will 400 (redirect_uri_mismatch) from docs.altinity.com until someone with Google Cloud Console access adds https://docs.altinity.com/altinity-sql-browser/sql.html as an authorized redirect URI on both Google OAuth clients referenced in docs/config.json. The demo/demo basic-auth entries work immediately without this.

Test plan

• npm test — full coverage gate passes (100% statements/functions/lines; new oauth-config.test.ts case for the static-file basePath)
• npx tsc --noEmit passes
• npm run build produces dist/sql.html
• Regression: npm run local's /sql route still resolves config.json correctly
• New scenario: served dist/sql.html + docs/config.json from a static server at a nested .../sql.html path, confirmed via Playwright the login screen renders all 4 saved connections with no failed requests
• After merge: confirm https://docs.altinity.com/altinity-sql-browser/sql.html and .../config.json are live (GitHub Pages rebuild is automatic on push to main)

🤖 Generated with Claude Code

https://claude.ai/code/session_017E2cHgYTiobxSJLnCxgCPj