- Header/footer moved to #lib/components/SiteChrome.svelte, returned by a universal
+layout.ts load only for non-immersive pages, so /start and the book reader never
download icon libraries, dropdowns or the bits-ui Sheet. /start: 36 -> 18 JS files,
133 -> 78 KB gzip.
- Header logo is a hashed asset (inlined), so it is cached with the build.
- inlineStyleThreshold 4096: tiny page/component CSS is inlined into the HTML.
- Umami is not loaded on /start.