[ositaemmanuel653-netizen]

What does this PR do?

Adds CSV/JSON export for a loaded stream record and a Claim All action for receiving streams.

Type of change

• Bug fix
• New feature / page / component
• Refactor
• Style / design fix
• Test coverage
• Documentation
• Dependency update

Related issue

Closes #780
Closes #782

Changes

File	Change
app/stream/[id]/page.tsx	Adds an Export History dropdown that downloads the loaded stream details and balances as CSV or JSON.
app/streams/page.tsx	Adds a confirmed Claim All flow that checks receiving streams, withdraws claimable balances, reports partial failures, and refreshes the list.
CHANGELOG.md	Documents both features under Unreleased.

Checklist

• npm run typecheck ? no errors
• npm run lint ? no warnings
• npm test ? all tests pass
• npm run build ? production build succeeds
• Tested in browser with Freighter on testnet
• No hue-named Tailwind colour classes added (black/white/gray only)
• Loading state handled for any new data-fetching UI
• Error state handled and displayed inline (no alert())
• 'use client' added only where genuinely needed
• CHANGELOG.md updated under [Unreleased]

Screenshots

Before	After
Not captured	Not captured

Notes for reviewers

• This repository does not expose stream-specific transaction-event history to this page. The CSV and JSON files contain the loaded stream record and balances, not a list of historical transactions.
• The available BatchTransferProcessor transfers tokens provided by a funder; it cannot call stream withdraw(). Claim All therefore submits one existing withdrawal transaction per claimable stream. Each requires a wallet approval and network fee.
• Tests and browser validation were not run, as requested.