- Post.cshtml.cs: load hero image, tag from SiteSettings in SetViewDataAsync
- Post.cshtml: show <img> with hero image in .doc-avatar when set,
fall back to emoji only if no image is configured
- .doc-avatar: circular crop with object-fit:cover, gold border
- doc-title now uses HeroTag from settings (not hardcoded)
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>