feat(mobile): chat pushes as iOS communication notifications with the dog's photo

[GSTJ]

Summary

Chat pushes on iOS now render iMessage-style, with the sender dog's photo and name, and group per conversation.

Stacked on #75 (base branch is the reply-action one; merge that first).

Details

• Real Swift Notification Service Extension (via @bacons/apple-targets): intercepts the chat push, downloads the sender's avatar, donates the messaging intent and re-renders the notification as a communication notification.
• Fallback contract respected everywhere: missing fields, failed avatar download, intent errors or the extension time budget expiring all deliver the original notification untouched. A broken extension can never eat a message.
• Notifications group per conversation via the match id thread.
• Server now sends mutableContent, senderName and senderAvatarUrl on chat pushes, using only the first APPROVED photo (which also stops unapproved sender images from leaking in that payload).
• Communication entitlement wired on both the app and the extension.
• Release heads-up: the entitlement must be enabled on the provisioning profile in the Apple Developer portal before device/store builds sign.

Testing steps

Needs a build with real push credentials (won't show in simulator).

1. From a second test account with a dog photo, send yourself a chat message with the app closed or in background.
2. The notification should show the sender dog's round photo and name, looking like an iMessage/WhatsApp notification instead of a plain one.
3. Send several messages from two different matches: notifications should stack grouped by conversation.
4. Reply from the notification (feature from the base PR): should still work exactly as before.
5. Remove the sender dog's photos (or use a dog with no approved photo) and send again: the notification should still arrive, just without the avatar.