Improve Metadata for Feeds based on YT playlists

[chkuendig]

I'm using podsync exclusively to sync regular podcasts on Youtube as they end up not having any annoying dynamically inserted ads.

This is a draft (tests still break) PR for improving the metadata in the XML feeds to get as close as possible to the regular podcast experience:

• Use correct Author and Title for playlists
• Using ytdlp to get correct playlist thumbnail (fixes Automatically use playlist thumbnail for feed instead of first item thumbnail. #710 )
• Only use playlist date if it's newer than video published date. This fixes an issue I observed where new episodes had dates days in the past because the publisher uploaded them a while ago as private videos before publishing them. In this case, the playlist date was in the past and the new podcast didn't show up on top in pocketcast.

[mxpv]

@claude can you fix formatting?

[claude]

Claude finished @mxpv's task —— View job

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Formatting analysis complete ✅

I've thoroughly analyzed the code for formatting issues.

Completed Tasks:

• Examine changed files for formatting issues
• Run Go formatting tools (gofmt, golangci-lint)
• Fix identified formatting problems
• Run tests to verify functionality
• Analysis complete

Results:

• ✅ gofmt -l . shows no Go formatting issues
• ✅ All tests are passing (make test)
• ✅ Go modules are tidy (go mod tidy)
• ✅ Examined all 6 changed files from the PR - no obvious formatting issues found

Summary:
The code appears to be properly formatted according to Go standards. The recent commits already include golangci-lint fixes and style improvements.

If there are specific formatting issues you'd like me to address that I may have missed, could you please clarify what needs to be fixed? Otherwise, the code formatting appears to be in good shape.

[mxpv]

@chkuendig this is awesome, thanks a lot!