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/reports/page-imagery-audit.md

@@ -1,5 +1,5 @@
 # Page Imagery Audit
 
-Checked 84 page-banner, section-background, and blog-featured-image references.
+Checked 85 page-banner, section-background, and blog-featured-image references.
 
 No missing mapped page imagery was detected.