Function mediaKeyIndex

mediaKeyIndex(
    manifest: {
        base_url?: string;
        tiles?: Record<string, Record<string, { key: string }>>;
        assets?: Record<string, Record<string, { key: string }>>;
    },
): Map<string, string>
Build the key -> id index from a parsed media-manifest.json.

Tile keys map to their demo id. Keys under assets (the banner, the architecture diagram, the screen recordings) are README media that is not a tile: they map to the empty string so the README scrape recognises them without trying to capture a demo for them.
Parameters
- manifest: {
      base_url?: string;
      tiles?: Record<string, Record<string, { key: string }>>;
      assets?: Record<string, Record<string, { key: string }>>;
  }
Returns Map<string, string>
- Defined in src/tests/screenshots/gallery-selection.ts:99