fix(blog): restore live blockquote styling and quote-mark SVG

- restores the migrated blog blockquotes to the live site’s visual treatment
- adds the self-hosted quote-mark SVG and matches its live positioning
- updates the extractor, audit scripts, and migration reports to reflect the blockquote work

www/tools/extract-fallback.mjs

@@ -83,6 +83,7 @@ function markdownFrom(html) {
     '';
   body = body
     .replace(/<(script|style|noscript|header|footer|nav|form)\b[\s\S]*?<\/\1>/gi, '')
+    .replace(/<blockquote[^>]*>([\s\S]*?)<\/blockquote>/gi, (_, value) => `\n\n> ${inline(value)}\n\n`)
     .replace(/<img[^>]+src=["']([^"']+)["'][^>]*alt=["']([^"']*)["'][^>]*>/gi, (_, src, alt) => {
       const local = asset(src);
       return local ? `\n\n![${text(alt)}](${local})\n\n` : '';