[WEB3] Frontend: Integrate Freighter for withdraw Action #202

[CMI-James]

Description

Integrate the frontend Withdraw action with Freighter/Soroban transaction flow so recipients can claim funds from incoming streams with wallet signing.

Closes #202

Changes proposed

What were you told to do?

I was asked to:

• implement withdraw transaction builder/wallet flow,
• map the Withdraw UI action to signing/submission,
• add success/error state handling and notifications.

What did I do?

Wired incoming Withdraw button to Soroban call path

Updated frontend/components/dashboard/dashboard-view.tsx:

• imports withdrawFromStream from frontend/lib/soroban.ts,
• adds handleIncomingWithdraw that:
  • calls Freighter/Soroban withdraw transaction,
  • shows toast loading/success/error states,
  • refreshes dashboard snapshot from backend after confirmation.

Extended IncomingStreams component for real withdraw callbacks

Updated frontend/components/IncomingStreams.tsx:

• added onWithdraw(stream) prop,
• added withdrawingStreamId prop for per-row loading state,
• replaced mock simulated withdraw with callback-driven action.

Kept standalone incoming page compatible

Updated frontend/app/incoming/page.tsx to pass required onWithdraw prop to IncomingStreams.

Check List (Check all the applicable boxes)

• My code follows the code style of this project.
• This PR does not contain plagiarized content.
• The title and description of the PR is clear and explains the approach.
• My commit messages styles matches our requested structure.
• My code additions will fail neither code linting checks nor unit test.
• I am only making changes to files I was requested to.

Screenshots / Testing Evidence

Validated with:

lint-staged hook passed on commit (frontend eslint task succeeded)
npm run build --workspace=frontend

Build currently fails in this environment due external Google Fonts fetch/network errors, unrelated to withdraw logic.