Fix justanothersystem.org photos: load manifest and images from CDN

Slideshow assets were gitignored and never deployed to lith. Changed
manifest path to use the server-local manifest-updated.json and image
base URL to the DO Spaces CDN where they already exist.

Co-Authored-By: Claude Opus 4.6 (1M context) <[e-mail]>

system/public/justanothersystem.org/index.html

···
   <div class="progress-bar" id="progressBar"></div>
 
   <script>
-    const ASSET_BASE = '/assets/justanothersystem/slideshow/';
-    const MANIFEST_URL = ASSET_BASE + 'manifest.json';
+    const ASSET_BASE = 'https://assets.aesthetic.computer/justanothersystem/slideshow/';
+    const MANIFEST_URL = '/manifest-updated.json';
     const SLIDE_DURATION = 8000;
     const ZOOM_DURATION = 4000; // ms for perspective zoom-out
     const KB_CLASSES = ['kb-a', 'kb-b', 'kb-c', 'kb-d'];