feat(renderer): status pages before Astro (RFC-0043 PR 1) - #162

What

Rollout PR 1 of RFC-0043 (status pages and maintenance mode), from #117: a site that cannot show its pages answers with one small, translated, self-contained page instead of plain text. Self-contained: no contract, no writer, no maintenance yet.

• @cloudhal/astro-renderer/status-page: the pure statusPage(state, input) → Response (statusPlain for machine paths, statusPageHtml for hooks) with the closed state set not-published (503, Retry-After: 3600, noindex), maintenance (503, Retry-After to the end), unavailable (503, 300), error (500, reference id only) and preview-expired (410, noindex). Every response is no-store on browser and edge with x-cloudhal-state and the page's own CSP (default-src 'none'); the document stays under 8 KB in every state and language and uses logical properties only. maintenance and preview-expired may carry the published site's typed theme tokens (brand, surface/text when they contrast, the font pairing).
• Served before Astro in the Site Worker entry (siteState in runtime-workerd.ts, memoised per request so Astro's getSource reads the pointer once), with GET /__cloudhal/health answering { "ok": true, "state": "published" | "not-published" } (the admin's /api/health shape plus state), a top-level catch and Astro 5xx → the error page. Status pages go through the existing render events.
• Language: host or path-prefix locale, then the site default, then English; RTL from the registry, Western digits for Arabic and Persian dates. The catalog (src/status-strings/) covers every registered Studio language: en.ts is hand-edited, the other 18 come from pnpm i18n:import (the exchange script gains a second source, status.json per locale, same hash guard), and catalog.ts is generated from the registry. Messages use simple ICU arguments only, so no compiler ships in the Worker. The 18 translations are AI drafts awaiting review, as Studio's.
• Theme hook: an optional statusPage export in src/theme.ts (StatusPageHook from @cloudhal/astro-renderer/status-page) returns a document only; it falls back to the built-in page on undefined, a throw, a non-string, > 64 KB or > 50 ms (logged once per state) and never runs for error. Loaded lazily through virtual:cloudhal/theme-hooks (import("/src/theme.ts")), so old theme copies get the built-in page.
• cloudhal dev draws each state on demand at /__cloudhal/status/<state> (?locale, ?page=coming-soon, ?message, ?until) through the same module and the project's hook.
• Starter: the blog's routes use statusPage/statusPlain as their fallback instead of the plain 503s.
• Behaviour change (changeset): an invalid or expired preview link answers 410 instead of silently showing the published page.

Not in this PR (RFC rollout PR 2): cloudhal build --published writing the status page as the static output for the Docker self-host path, the Caddyfile 503 block and the self-host guide.

Tests run (only the touched files, per the owner's machine rule): packages/astro-renderer/test/status-page.test.ts (29), packages/cli/test/cloudflare-status.test.ts (5, workerd: the page before the first publish with the theme hook, machine paths, health, preview-expired, the publish flip), cloudflare-multisite.test.ts (5, with the new two-host check: an unpublished site on its own host gets its page with no-store and Vary: Host, its siblings serve), cloudflare.test.ts + packaging.test.ts (20), dev-status.test.ts (1), apps/studio/test/i18n-messages.test.ts (9). pnpm lint, pnpm typecheck, pnpm size:check, pnpm design:lint and node scripts/i18n-exchange.ts check green.

Checklist

• pnpm check and cargo test --workspace pass locally (not run: only the touched test files, lint, typecheck, size and design lint; CI runs the rest)
• Contract change? pnpm gen was run and generated files are committed (docs/adr/0001) — no contract change
• User-visible change in a published package? pnpm changeset added
• Commits are signed off (git commit -s, DCO)
• Docs / AGENTS.md updated if behaviour or commands changed

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