Fix (formatVideo): guard against undefined title and improve artist/title extraction

[1ly4s0]

This PR makes the formatVideo helper more robust by ensuring video.title is always treated as a string and by using a safer splitting and regex strategy to extract artist and title. Previously, calling video.title.split('-') would throw when video.title was undefined, and the simple match(/([^,]*)-(.*)/) could fail or produce unintended results.

Changes include:

1. Ensure titleStr is always a string.

   • Coerce video.title to '' if it isn’t a string, then trim().
   • Assign this to video.original_title.

2. Safer split logic.

   • Use titleStr.split('-') only to detect presence of a hyphen without risking a TypeError.

3. Improved regex extraction.

   • Apply /^([^–-]+)[–-](.+)$/ to handle both ASCII - and en-dash –, capturing exactly two groups: artist and title.
   • Trim both groups.

4. Fallback behavior.

   • If regex doesn’t match, default to artist = '' and leave title = titleStr.

5. Minor cleanup:

   • Log errors via console.error('formatVideo failed:', err) for better debugging.
   • Preserve existing date formatting logic untouched.

Why:

• Prevents TypeError when video.title is undefined or not a string.
• Handles different dash characters and whitespace more cleanly.
• Provides a safe fallback for unexpected title formats.
• Improves maintainability and reduces test failures in edge cases.

Testing:

• Added unit tests covering:
  • video.title as undefined or non-string.
  • Titles without any dash.
  • Titles with ASCII dash and en-dash.
  • Malformed titles that shouldn’t match the regex.
• Verified existing integration scenarios still produce the correct artist, title, and publishedAt.