Cap Apple Music artwork resolution to 1000x1000 (#3177)

Apple Music API returns artwork URLs with the maximum available resolution
(e.g. 6605x6605, 3000x3000) which causes excessive bandwidth usage, slower
page loads, and unnecessary memory consumption. Since Apple Music artwork
URLs support dynamic sizing via {w}x{h} placeholders, cap the requested
dimensions to 1000x1000 which is sufficient for all UI contexts. The
existing image proxy can further downscale for thumbnails as needed.

https://claude.ai/code/session_01AxXvTSeiZyCmnNqYLtfhLH

Co-authored-by: Claude <[email protected]>