Responsive media metadata

The shared image normalization and rotating-media pipeline accepts a URL string, a single image map, or a list mixing strings and maps. Existing inputs retain their behavior. Hero-like blocks using that pipeline can pass optional browser image metadata in each map:

sections:
  - type: hero
    content:
      title: A useful next chapter
      media:
        images:
          - url: /images/hero-1280.webp
            alt: An accurate description when the image conveys information
            srcset: /images/hero-640.webp 640w, /images/hero-1280.webp 1280w
            sizes: "(max-width: 700px) 100vw, 70vw"
            width: 1280
            height: 720
            position: 50% 40%

src remains an alias for url. srcset and sizes use normal browser syntax and Hugo attribute escaping; provide actual site-visible candidate URLs. Core does not generate variants, inspect remote images or infer the rendered slot width. Account for any deployment subpath in candidate URLs. Intrinsic width and height describe the image’s pixel dimensions and aspect ratio, not a CSS layout size. Only positive decimal integer dimensions are emitted; missing, zero, negative and malformed values are omitted.

Normalization preserves the existing position/object_position, mobile_position/object_position_mobile and kenburns_preset/preset metadata. This addition does not change how individual block renderers consume positioning. Existing motion, object-fit, first-image priority, eager/lazy loading and rotation remain unchanged. Decorative backgrounds and inactive rotation frames still receive empty alt text and aria-hidden; content images retain their existing accessible description behavior.

The compatibility fixture current-site-baseline/responsive-media/ proves metadata reaches a real hero. Rendered Go tests also exercise string/map/mixed list inputs, rotation, decorative semantics, invalid dimensions and Hugo attribute escaping. Browser source selection is additional evidence; synthetic fixture candidates do not demonstrate real transfer savings. Consumers must verify their own assets, breakpoints, visual states and measured performance.

Optional override CSS

assets/css/foundry-overrides.css is optional. Missing, empty and whitespace-only resources produce no stylesheet request. Nonempty source retains its late cascade position, development URL and production minification, fingerprint and integrity attributes. A source containing only comments is still nonempty and follows the normal resource pipeline.

Shield shell adoption

Shield places charset before the extensible head-start.html hook. Its shell test renders a long multibyte hook with and without minification and asserts the charset declaration finishes within the first 1024 bytes.

When upgrading from Shield v0.1.15, review site head-end.html and other custom SEO hooks: the current Shield shell renders foundry/seo/render.html itself. Remove a redundant site invocation rather than emitting duplicate metadata or structured data. Shield also avoids duplicate home/site titles. Keep any site-owned shell override under an explicit compatibility and review boundary.