Design the client for a money transfer app's transaction history screen. Requirements: infinite-scroll pagination, recent history available offline, new transactions appearing at the top in real time, and no flicker or duplicates on low-end devices with a flaky signal.
The local DB (SQLite/SwiftData) is the single source of truth and the screen observes only the DB. Server pages (cursor based) and real-time events (push/socket) both upsert into the DB, deduplicated by id and ordered by server timestamp. The UI updates partially with a diffable snapshot, and for low-end devices and bad signal you use small pages, timeouts, retries, and a "last synced" indicator.
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