Improve existing hooks.

[koculu]

Summary

Page hooks now run on every page render, including dev-server re-renders. The package also exports the types hook and template authors need, and the ts-ssg README is corrected to match the code.

Page hooks run on every render

onPageStart, onPageRendered and onPageWritten used to fire only in full builds. Pages re-rendered in serve went through buildPage, which skipped them, so a hook that post-processed HTML worked in build and silently stopped working in serve after the first edit.

• Full builds, eager renders of an edited page, and on-request renders after a shared change all go through one writePageWithHooks method in content-state.ts, so build and serve produce the same output.
• With writeErrorPages (dev), a throwing hook during a re-render writes an error page, as it already did in full builds.
• buildPage had no other callers and is removed.
• onConfigResolved, onContentDiscovered, onNavigationBuilt, onStylesWritten and onBuildComplete still run once per full build, deliberately. For example, onContentDiscovered can do expensive work, such as the studio writing its preview files.

Exported types

@purestack/ts-ssg now exports:

• Build and hooks: BuildOptions, BuildCountSummary, BuildContext, PageRenderResult, ResolvedContentFile, WriteStylesResult
• Templates: PageTemplate, PageTemplateInput, PageTemplateMap, PageInfo, PageFrontmatter
• Config and components: SiteConfig, SiteConfigInput, TsSsgContext

Previously a hook's context or a template's input couldn't be typed without importing internal paths.

README corrections

• Quick starts: both examples passed site config at the top level and didn't compile; they now use siteConfig and build.siteConfig.
• Templates: the example imported a type that wasn't exported; it now compiles and documents the template input.
• Components: replaces a stale 16-item list with the component reference, explains options.components, and corrects the claim that components never run in the browser (PageScript, RegorApp).
• Theming: names the real API, themeSkins and registerSkin from @purestack/ts-style; builtInSkins doesn't exist.
• Markdown: documents the real siteConfig.mdx options in place of a nonexistent BuildInput.mdx.
• Build hooks: when each hook runs, that page.html changes in onPageRendered are written, that hooks need the programmatic API, and an example.
• API surface: lists exactly what the package exports.

Every README code example was type-checked against the real exports.

Testing

• New incremental tests cover:
  • page hooks firing in the full build, for an edited page, and for a page rendered on request after a header edit;
  • page.html changes reaching disk;
  • a failing hook producing an error page during a re-render.
• The ts-ssg suite passes, and Biome and TypeScript 7 are clean.