Reposting for the systems engineering. The background task system using URLSessionConfiguration.background is the most underrated part — iOS background execution is notoriously fragile, and this implementation handles it correctly: no automatic retry on gpt-image-2 timeout (because you cannot know if OpenAI is still processing), 60-second same-hash deduplication to prevent double billing, manual re-generate with input image restoration. This is production-grade reliability thinking applied to a side project. The rest of the AI creative stack sits on top of a genuinely solid foundation.