Recaps become something you can listen to

I can now listen to a recap instead of only reading it, leave partway through, and pick up where I stopped. The product also shows me when a recap is still being prepared, which makes the whole process feel much more tangible.

Changelog

• Added narrated recaps with playback progress and resume support.
• Added live recap processing status so users can see when recaps are still being prepared.
• Improved podcast onboarding by running initial catch-up automatically after subscribing.
• Improved recap reliability by moving to a more robust end-to-end processing pipeline.
• Delivered the first live production rollout on summ.live for end-to-end recap usage.