feat(tutorial): implement comprehensive tutorial system with step guidance

- Added tutorial controller to manage tutorial state and progress.
- Introduced HelpButton component for contextual help throughout the application.
- Created various tutorial steps for onboarding and feature guidance.
- Integrated tutorial prompts in multiple components (ChildrenListView, LoginButton, ScheduleModal, etc.) to enhance user experience.
- Implemented logic to show tutorials based on user actions and state.
- Added functionality to dismiss and skip tutorial sessions.
- Established a mechanism to hydrate tutorial state from user profile.

backend/models/user.py

@@ -25,6 +25,8 @@ class User(BaseModel):
     timezone: str | None = None
     email_digest_enabled: bool = True
     push_notifications_enabled: bool = True
+    tutorial_enabled: bool = True
+    tutorial_progress: dict = field(default_factory=dict)
 
     @classmethod
     def from_dict(cls, d: dict):
@@ -51,6 +53,8 @@ class User(BaseModel):
             timezone=d.get('timezone'),
             email_digest_enabled=d.get('email_digest_enabled', True),
             push_notifications_enabled=d.get('push_notifications_enabled', True),
+            tutorial_enabled=d.get('tutorial_enabled', True),
+            tutorial_progress=d.get('tutorial_progress', {}) or {},
             id=d.get('id'),
             created_at=d.get('created_at'),
             updated_at=d.get('updated_at')
@@ -82,5 +86,7 @@ class User(BaseModel):
             'timezone': self.timezone,
             'email_digest_enabled': self.email_digest_enabled,
             'push_notifications_enabled': self.push_notifications_enabled,
+            'tutorial_enabled': self.tutorial_enabled,
+            'tutorial_progress': self.tutorial_progress,
         })
         return base