Push notification updates - bug fixed were push notifications weren't correctly configured

1.⁠ ⁠Push Notifications Agora now sends push notifications via Apple Push Notification service (APNs). Three notification types are in use: • Morning Story — a daily reminder when today's news story is published • Friend Played — fires once per friend per day when a friend completes a match • Streak at Risk — an evening nudge if the user hasn't played today and has an active streak All notification types are off by default for new users. Users opt in via Profile → Settings → Notifications, where each type can be toggled individually. Notification frequency is also tiered automatically by engagement level — infrequent players receive fewer types than active daily players. Device tokens are registered only after the user grants notification permission. 2.⁠ ⁠Account Persistence Between Sessions (Keychain) The app wraps agoragame.com in a WKWebView. WKWebView's localStorage is not reliably persisted when the app uses a remote server.url configuration, which caused users to be logged out on every relaunch. To fix this, the app now stores Supabase authentication tokens in the device Keychain (kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly, ThisDeviceOnly — excluded from iCloud Keychain backup). Only keys prefixed with "sb-" (Supabase auth keys) are accepted; all other keys are rejected at the native bridge layer. This is used exclusively to keep the user's session alive between app launches. 3.⁠ ⁠Security Improvements Game session integrity is now validated server-side. The server independently verifies each question answer and calculates the result — the client no longer submits scores or balances directly. This change is transparent to users and does not affect gameplay.