Cloud.vue's viewPaidItem() called window.open() instead of the in-app
MediaLightbox, and its content.owned-get fetch had a 60s timeout with no
loading indicator and a swallowed catch. Moves the fetch/decode/route logic
into a new usePaidItemViewer composable: image/video route to a second
MediaLightbox instance fed a synthetic FileBrowserItem, audio still goes to
the global bottom-bar player, and anything with no in-app viewer keeps
today's browser-tab fallback. The Paid Files row now shows an "Opening…"
spinner (matching PeerFiles' existing treatment) for the fetch's duration,
becomes non-interactive to prevent double-fetch, and a real error surfaces
through the view's existing alert-error block instead of an empty catch.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
