fix(site): include code-referenced images in static output

The docs header logo and favicon 404 on production because the
static copy step only scanned markdown for image references. Scan
site sources as well and fail the build when one goes missing.

site/scripts/prepare-static-output.mjs

@@ -21,6 +21,7 @@ async function copyDirectory(source, destination) {
 
 const markdownImagePattern = /!\[[^\]]*]\(([^)\s]+)(?:\s+["'][^"']*["'])?\)/g
 const htmlImagePattern = /<img\b[^>]*?\bsrc=["']([^"']+)["'][^>]*>/gi
+const siteImagePattern = /["'(]\s*(\/[A-Za-z0-9_./-]+\.(?:avif|gif|jpe?g|png|svg|webp))/gi
 
 function imageTargets(markdown) {
   const prose = markdown.replace(/```[\s\S]*?```/g, '')
@@ -30,6 +31,22 @@ function imageTargets(markdown) {
   ].map((match) => match[1])
 }
 
+function isOutsideDocsPublic(relative) {
+  return relative.startsWith('..')
+    || path.isAbsolute(relative)
+    || relative === 'public'
+    || relative.startsWith(`public${path.sep}`)
+}
+
+async function copySources(sources) {
+  for (const source of sources) {
+    if (!await pathExists(source)) continue
+    const destination = path.join(distDir, path.relative(paths.docsDir, source))
+    await fs.mkdir(path.dirname(destination), { recursive: true })
+    await fs.copyFile(source, destination)
+  }
+}
+
 async function copyReferencedDocImages(records) {
   const sources = new Set()
 
@@ -45,27 +62,52 @@ async function copyReferencedDocImages(records) {
         : path.resolve(sourceDirectory, pathname)
       const relative = path.relative(paths.docsDir, source)
 
-      if (
-        relative.startsWith('..')
-        || path.isAbsolute(relative)
-        || relative === 'public'
-        || relative.startsWith(`public${path.sep}`)
-      ) {
-        continue
-      }
+      if (isOutsideDocsPublic(relative)) continue
 
       sources.add(source)
     }
   }
 
-  for (const source of sources) {
-    if (!await pathExists(source)) continue
-    const destination = path.join(distDir, path.relative(paths.docsDir, source))
-    await fs.mkdir(path.dirname(destination), { recursive: true })
-    await fs.copyFile(source, destination)
+  await copySources(sources)
+  console.log(`Copied ${sources.size} referenced documentation images.`)
+}
+
+async function siteSourceFiles() {
+  const files = [path.join(paths.siteDir, 'index.html')]
+  const srcDir = path.join(paths.siteDir, 'src')
+  const entries = await fs.readdir(srcDir, { recursive: true, withFileTypes: true })
+  for (const entry of entries) {
+    if (entry.isFile() && /\.(?:jsx?|css)$/.test(entry.name)) {
+      files.push(path.join(entry.parentPath || entry.path, entry.name))
+    }
+  }
+  return files
+}
+
+async function copySiteReferencedImages() {
+  const sources = new Set()
+  const missing = []
+
+  for (const file of await siteSourceFiles()) {
+    const content = await fs.readFile(file, 'utf8')
+    for (const match of content.matchAll(siteImagePattern)) {
+      const pathname = match[1]
+      const source = path.join(paths.docsDir, pathname.replace(/^\/+/, ''))
+      const relative = path.relative(paths.docsDir, source)
+
+      if (isOutsideDocsPublic(relative)) continue
+
+      if (await pathExists(source)) sources.add(source)
+      else missing.push(`${path.relative(paths.siteDir, file)}: ${pathname}`)
+    }
   }
 
-  console.log(`Copied ${sources.size} referenced documentation images.`)
+  if (missing.length > 0) {
+    throw new Error(`Site-referenced images missing under docs/:\n- ${missing.join('\n- ')}`)
+  }
+
+  await copySources(sources)
+  console.log(`Copied ${sources.size} site-referenced images.`)
 }
 
 async function createRouteEntry(route, shell) {
@@ -86,6 +128,7 @@ async function main() {
 
   await copyDirectory(path.join(paths.docsDir, 'public'), distDir)
   await copyReferencedDocImages(records)
+  await copySiteReferencedImages()
 
   const customDomain = (await fs.readFile(path.join(distDir, 'CNAME'), 'utf8')).trim()
   if (customDomain !== expectedCustomDomain) {