seo-images-medialisted

# seo-images-media (M9) Accessible, well-described media is read by both ranking systems and AI extractors — alt text is the primary semantic handle for an image. Reference: `references/schema-tier1.md` (VideoObject row). ## Audits Working from the PageSnapshot (`rendered_dom` if present, else `raw_html`): 1. **Alt presence**: every content `<img>` has an `alt` attribute. Distinguish decorative images (`alt=""` + `role="presentation"` is correct, not a finding) from missing `alt` entirely (fail). 2. **Alt quality**: not empty on a content image; not the filename (`IMG_2031.jpg`); not duplicated verbatim across distinct images; not keyword-stuffed (comma-separated keyword lists are an anti-pattern). Alt should be descriptive and contextual to surrounding content. Target length ~80-140 chars — long enough to be specific, short enough that screen readers/AI don't truncate. 3. **Dimensions**: `width` and `height` set on `<img>` (or aspect-ratio reserved in CSS) to prevent layout shift (CLS, a Core Web Vitals input — defer the CWV measurement itself to the perf module). 4. **Format**: flag legacy `jpg`/`png` where a modern format (WebP/AVIF) or a responsive `<picture>`/`srcset` would serve smaller bytes. 5. **Video**: embedded video (`<video>`, YouTube/Vimeo iframe) without `VideoObject` JSON-LD — coordinate with M5; required/recommended props in `references/schema-tier1.md`. ## Fixes - **AUTO** (`fixable: auto`): add `width`/`height` to `<img>` from the source asset's intrinsi