Render Modal as real markup; drain scripts via CaptureScript (#2742)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

shared/ui/Photo.astro

@@ -1,9 +1,5 @@
 ---
-// The lightbox page passes a resolved `photo` object taken from the
-// horizontal-filtered list; the Eleventy reference's background/img src follows
-// that same filtered order, so a direct object is the faithful mapping.
-// TODO: the id-based lookup into photos.json and the `{% else %}` svg.html
-//       fallback branch (ui/svg.html) — both unused on the lightbox page.
+// Lightbox passes a resolved `photo` object from the horizontal-filtered list.
 interface Photo {
   file: string
   title?: string