Push Notifications

Covers the full notification stack for iOS and macOS, from requesting permissions and registering device tokens to scheduling local notifications, handling remote APNs payloads, and setting up notification actions and categories. The source walks through the permission flow (including provisional and critical alerts), shows how to wire up AppDelegate in SwiftUI to receive tokens, explains trigger types for local notifications (time, calendar, location), and includes payload structures for remote pushes. Helpful if you're implementing notifications from scratch or debugging why tokens aren't registering or notifications aren't appearing. The common mistakes section and review checklist are worth reading even if you've shipped notification code before.