Add push notification functionality with tests and digest scheduler

- Implemented push subscription API with tests for subscribing and unsubscribing users.
- Created web push notification tests triggered by child actions.
- Added digest scheduler to send email digests to users at 9 PM local time.
- Developed utility functions for creating and validating digest action tokens.
- Integrated web push sender to handle sending notifications to users.
- Added service worker for handling push notifications in the frontend.
- Created a push opt-in component for user notification preferences.
- Implemented tests for the push opt-in component to ensure correct behavior.
- Updated frontend services to manage push subscriptions and permissions.

backend/models/digest_action_token.py

@@ -0,0 +1,44 @@
+from dataclasses import dataclass
+from models.base import BaseModel
+
+
+@dataclass
+class DigestActionToken(BaseModel):
+    user_id: str
+    child_id: str
+    entity_id: str
+    entity_type: str   # 'chore' or 'reward'
+    action: str        # 'approve' or 'deny'
+    expires_at: str    # ISO timestamp
+    used: bool = False
+    signature: str = ''
+
+    @classmethod
+    def from_dict(cls, d: dict) -> 'DigestActionToken':
+        return cls(
+            user_id=d.get('user_id'),
+            child_id=d.get('child_id'),
+            entity_id=d.get('entity_id'),
+            entity_type=d.get('entity_type'),
+            action=d.get('action'),
+            expires_at=d.get('expires_at'),
+            used=d.get('used', False),
+            signature=d.get('signature', ''),
+            id=d.get('id'),
+            created_at=d.get('created_at'),
+            updated_at=d.get('updated_at'),
+        )
+
+    def to_dict(self) -> dict:
+        base = super().to_dict()
+        base.update({
+            'user_id': self.user_id,
+            'child_id': self.child_id,
+            'entity_id': self.entity_id,
+            'entity_type': self.entity_type,
+            'action': self.action,
+            'expires_at': self.expires_at,
+            'used': self.used,
+            'signature': self.signature,
+        })
+        return base

backend/models/push_subscription.py

@@ -0,0 +1,29 @@
+from dataclasses import dataclass
+from models.base import BaseModel
+
+
+@dataclass
+class PushSubscription(BaseModel):
+    user_id: str
+    endpoint: str
+    keys: dict  # {'p256dh': str, 'auth': str}
+
+    @classmethod
+    def from_dict(cls, d: dict) -> 'PushSubscription':
+        return cls(
+            user_id=d.get('user_id'),
+            endpoint=d.get('endpoint'),
+            keys=d.get('keys', {}),
+            id=d.get('id'),
+            created_at=d.get('created_at'),
+            updated_at=d.get('updated_at'),
+        )
+
+    def to_dict(self) -> dict:
+        base = super().to_dict()
+        base.update({
+            'user_id': self.user_id,
+            'endpoint': self.endpoint,
+            'keys': self.keys,
+        })
+        return base

backend/models/user.py

@@ -22,6 +22,8 @@ class User(BaseModel):
     deletion_attempted_at: str | None = None
     role: str = 'user'
     token_version: int = 0
+    timezone: str | None = None
+    email_digest_enabled: bool = True
 
     @classmethod
     def from_dict(cls, d: dict):
@@ -45,6 +47,8 @@ class User(BaseModel):
             deletion_attempted_at=d.get('deletion_attempted_at'),
             role=d.get('role', 'user'),
             token_version=d.get('token_version', 0),
+            timezone=d.get('timezone'),
+            email_digest_enabled=d.get('email_digest_enabled', True),
             id=d.get('id'),
             created_at=d.get('created_at'),
             updated_at=d.get('updated_at')
@@ -73,5 +77,7 @@ class User(BaseModel):
             'deletion_attempted_at': self.deletion_attempted_at,
             'role': self.role,
             'token_version': self.token_version,
+            'timezone': self.timezone,
+            'email_digest_enabled': self.email_digest_enabled,
         })
         return base