Add Framev2

[willyogo]

As a user, I want to be able to embed any Framev2 as a fidget on my Feed/Homebase or Profile Space. Similarly, I want to be able to use any Framev2 that's embedded on a space.

1. Integration of Frame v2 as a Fidget:
   • Allow users to embed Frame v2 by inputting the Frame’s URL.
   • Utilize the Farcaster Frame v2 spec to fetch and render the embedded Frame.
2. Authentication Setup:
   • Implement the authentication flow to generate a unique auth token for each user accessing a Frame.
   • Ensure the token is passed to the Frame, providing context about the user per the Frame v2 spec.

Frame v2 spec: https://docs.farcaster.xyz/developers/frames/v2/

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Acceptance Criteria

Minimum Lovable Product (MLP)

1. Embedding Functionality:

   • Users can embed any Frame v2 in the Frame Fidget by pasting a valid Frame URL.
   • The Frame renders properly based on the provided URL.

2. Authentication:

   • A unique auth token is generated for each user when a Frame is accessed.
   • The Frame receives user context when rendered.

   Post-MLP Enhancements

3. Notification Subscription:

   • When a Frame is added, the user is automatically subscribed to notifications related to that Frame.
   • Notifications are displayed to users in the nounspace interface.