feat: implement license transfer UI with recipient safeguards

[Tee-Gee57]

Description

Implement the license transfer flow in the buyer library, exposing the existing transfer_license capability through a secure, multi-step user interface with comprehensive recipient validation and safeguards.

This PR adds the transferLicense method to PromptHashClient, including a mock implementation, and introduces a dedicated TransferLicense component that guides users through reviewing and confirming a license transfer.

The flow validates recipient addresses for both network and format, prevents self-transfer and duplicate ownership scenarios, clearly communicates fees and the permanent loss of access associated with transferring a license, and handles cancellation, failure, retry, and success states.

On successful transfer, the UI uses the real transaction hash returned by the contract and refreshes the buyer library/access state.

Closes #19

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Refactor / code cleanup
• CI / tooling / developer experience

How Has This Been Tested?

The transfer flow was tested across the primary success, validation, cancellation, and failure scenarios.

• Manual testing (describe steps below)
• Automated tests added / updated

Test steps:

1. Open the BuyerLibrary and locate a prompt with an eligible transferable license.

2. Select the new Transfer action on the prompt card.

3. Enter a recipient address and verify that invalid or incorrectly formatted addresses are rejected.

4. Verify that addresses belonging to a different network are rejected.

5. Attempt to transfer the license to the current owner's own address and verify that self-transfer is prevented.

6. Attempt to transfer to an address that already owns the license and verify that duplicate ownership is prevented.

7. Continue with a valid recipient and verify the multi-step review screen displays:

   • Prompt information.
   • Recipient address.
   • Applicable fees.
   • Clear warning that transferring the license permanently removes the current owner's access.

8. Cancel the transfer during the review/confirmation flow and verify that no transaction is submitted.

9. Confirm a valid transfer and verify that the real transaction hash returned by the contract is displayed/used.

10. Verify that the buyer library and relevant access states refresh after a successful transfer.

11. Simulate a failed transaction and verify that an appropriate error state is displayed without incorrectly updating ownership.

12. Use the retry flow after a failure and verify that the user can attempt the operation again.

13. Verify that existing BuyerLibrary functionality remains unaffected.

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented on complex or non-obvious areas of the code
• I have updated documentation where necessary
• My changes generate no new warnings
• New and existing tests pass locally
• I have checked that no sensitive information (keys, passwords, tokens) is committed

Screenshots (if applicable)

The PR introduces a new transfer flow and UI modal.

Screenshots/screen recordings should demonstrate:

• Transfer button on BuyerLibrary prompt cards.
• Recipient address entry and validation.
• Multi-step review screen.
• Fees and recipient information.
• Permanent license-loss warning.
• Cancellation state.
• Transfer failure and retry state.
• Successful transfer with transaction confirmation.

[drips-wave]

@Tee-Gee57 Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

Learn more about application limits