perf(site): compile the registry once per build, not twice

[maehr]

Stacks on #136. Both change the same astro.config.mjs call site. Retarget to staging once #136 lands; until then this PR shows #136's commits too.

The bug

An instrumented npx astro build calls compileRegistry twice.

Astro loads astro.config.mjs in a module graph of its own, separate from the one the pages render in. src/lib/registry.ts is therefore instantiated twice in one process, and the module-level memo is not shared between the two copies.

Compiling the real registry takes about 2.6s and materialises 86,397 references, so the second pass costs that time and a second copy in memory on every build and every dev start.

Why the obvious fix does not work

The issue suggested building the predicate lazily inside the sitemap filter callback. That does not help: the two module graphs never share a module variable, whenever the first call happens. Laziness moves the second compile, it does not remove it.

The fix

Memoise on globalThis under a registered symbol, which is the one scope both graphs agree on.

const CACHE_KEY = Symbol.for('textrefs.compiledRegistry');
host[CACHE_KEY] ??= compileRegistry();

Lifetime is unchanged — the process, exactly as the module memo was — so a dev server still needs a restart after the data/ submodule changes. No new staleness.

Measured

	compileRegistry calls	pages built
before	2	259,812
after	1	259,812

Both runs instrumented at the top of compileRegistry, both exit 0. The instrumentation was removed and the tree re-checked after each run.

On the test

Two module graphs cannot be simulated in node:test, so nothing here asserts the cross-graph sharing directly, and I have not pretended otherwise.

What is testable is the footgun the change creates: the fixture short-circuit must stay above the cache. If it slips below, every fixture-backed test silently compiles the real registry and leaves it on the global. src/lib/registry.test.ts fails when the two lines are swapped, and its runtime jumps from 0.3ms to 871ms — which is the real compile happening.

Verification

• npm run verify — 123 tests pass, 259,812 pages built, all internal links valid

Closes #131

🤖 Generated with Claude Code

https://claude.ai/code/session_011HLhfpsrWxq56jnZr1gD8B

[Copilot]

🟡 Changes recommended

src/lib/registry.ts likely introduces a TypeScript type error by using a non-unique symbol (Symbol.for(...)) as a computed key in a type literal, which can break typechecking/builds.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

This PR addresses a build-time performance issue where compileRegistry() was invoked twice due to Astro loading astro.config.mjs in a separate module graph from page rendering. It introduces a globalThis-backed cache for the compiled registry (shared across both graphs) and (stacked from #136) refactors sitemap exclusion logic into a dedicated src/lib/sitemap.ts module.

Changes:

• Memoize the compiled registry on globalThis via a registered Symbol to avoid double compilation per build/dev start.
• Replace the old noindex predicate module with sitemap exclusion logic, including excluding /cite/ redirects and untranslated /de/ fallback pages from the sitemap.
• Add tests for the sitemap exclusion behavior and for the fixture short-circuit staying above the global cache.

File summaries

File	Description
astro.config.mjs	Switches sitemap filter to use buildSitemapExclusion() from the new sitemap module.
src/lib/registry.ts	Moves the compiled-registry memoization from a module variable to a globalThis symbol cache.
src/lib/registry.test.ts	Adds regression tests ensuring fixture mode does not populate the global cache and repeated loads reuse the same registry.
src/lib/sitemap.ts	New sitemap exclusion rules (draft records, /cite/ redirects, untranslated locale fallbacks) and shared draftRecordIris().
src/lib/sitemap.test.ts	Adds coverage for the new sitemap exclusion rules.
src/pages/cite/[...alias].astro	Adds noindex meta for /cite/ aliases that redirect to draft records.
src/lib/noindex.ts	Deleted (replaced by src/lib/sitemap.ts).
src/lib/noindex.test.ts	Deleted (replaced by src/lib/sitemap.test.ts).

Review details

• Files reviewed: 8/8 changed files
• Comments generated: 1
• Review effort level: Lite

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