Podcast site with episode player

Build a website for a podcast.

Core features:
1. Episode list pulled from RSS
2. Episode page: player, show notes, transcript, guests
3. Newsletter signup for new episodes
4. SEO per episode (JSON-LD PodcastEpisode)
5. Sponsor slot management

Data: episodes, guests, sponsors, subscribers.
Must-haves: sticky mini player, share links with timestamp, dark mode.