Learn page shows network error message when no search results

Issue type

UI bug (incorrect info or interface appearance)

Description with steps to reproduce

1. Go to learn page
2. Enter text into search field that won't find any video

Actual behavior: Network error message shows ("Sorry, we are unable to load [...]")
Expected behavior: "No results found" or similar is shown

Supporting files, videos and screenshots

In which versions of MuseScore Studio is this issue present?

main

Regression

No.

Operating system

Windows 10

Additional context

Found by coderabbitai (https://github.com/musescore/muse_framework/pull/197#discussion_r3722188303)

Checklist

• This report follows the guidelines for reporting bugs and issues
• I have verified that this issue has not been logged before, by searching the issue tracker for similar issues
• I have attached all requested files and information to this report
• I have attempted to identify the root problem as concisely as possible, and have used minimal reproducible examples where possible

Reproduce the issue on the Learn page by searching for text with no matching video, then trace the search-result handling from the page's search field. Done means an empty-result search shows a “No results found” message instead of the network error; verify both matching and non-matching searches.