ci: continuous integration with draft content

[Aryex]

Summary

Implements the new deployment model proposed in #276:

• main becomes the single source of truth, replacing the main → public promotion flow.
• Unreleased content is hidden by draft flags instead of long-lived branches.

Issue link

Closes #276

Content Changes

• CONTRIBUTING.md — replaces the two-branch overview with the trunk-based deployment model: draft: true for unreleased pages, the <Draft> component for partial content, the two draft rules (no manual sidebar entries for draft pages; no links from published pages to draft pages), release-day process, and structural-change guidance.
• src/content/docs/concepts/client-features/client-side-caching.mdx and src/content/docs/how-to/connections/resilience-best-practices.mdx — pending remark formatting applied (separate commit, no content changes).

Implementation

• deploy.yml — push trigger and deploy-job guard changed from public to main.
• ci-cd.yml, static-checks.yml, check-csharp-examples.yml — public removed from PR branch filters.
• src/components/Draft.astro (new) — inline equivalent of Starlight's page-level draft: true: renders children only in dev mode ({import.meta.env.DEV && <slot />}), so wrapped content is excluded from production builds but reviewable in pnpm dev. Releasing content = deleting the wrapping tags.

ATTENTION ⚠️

Reviewers, please confirm the following commits are ready for deployment. merging this will cause a deployment immidiately.

• docs: Java server-assisted client-side caching #251 — Java server-assisted client-side caching please confirm the Java release with server-assisted CSC has shipped
• docs: Debug documentation and usages #267 — Debug documentation and usages
• docs(go): add inflightRequestsLimit support for Go #270 — Go inflightRequestsLimit support

Remaining manual steps after merge (repo admin):

Testing

• pnpm build — 110 pages built, all internal links valid.
• pnpm format — clean (formatting drift committed separately).
• <Draft> component verified locally: wrapped content absent from production build HTML; rendered by the dev server.
• Verified draft: true pages are excluded from production builds and drop out of autogenerated sidebar sections gracefully.

Checklist

Before submitting the PR make sure the following are checked:

• This Pull Request is related to one issue.
• Commit message has a detailed description of what changed and why.
• All commits are signed off with --signoff flag.
• pnpm build runs successfully.
• Links have been checked for validity.
• Destination branch is correct - main or release
• Create merge commit if merging release branch into main, squash otherwise.

[jeremyprime]

May want to update PR checklist with line item on draft usage.

[Aryex]

After some discussions, we decided to go with a two branch approach instead, keeping the draft contents. See CONTRIBUTING.md for more details.

[Aryex]

Only specific maintainers are allowed force pushes to public. Force pushing are disabled in general.

[jeremyprime]

Or hotfixes always go to main and then open a PR from main to public. That avoids backporting and divergence between public and main.

[jeremyprime]

Or just open a PR from main to public instead of force pushing. Merging should not cause any issues now that main and public are in sync, and it avoids the need for special push permissions. Force pushing can be an alternate option if main and public ever diverge.

[jeremyprime]

Warning in PR description is no longer applicable since those are going into main and will not go live right away. Instead the question is which open PRs need to tag pages or elements as draft to avoid going live until the underlying features are released.