fix(send): wire refreshQuote into Send and PayRequest QuoteCard (#39)

[ghzhost]

Summary

Resolves #39.

Problem

QuoteCard has an existing Refresh button controlled by the onRefresh prop and an expired warning state telling users to refresh their rate, but neither Send.tsx nor PayRequest.tsx passed onRefresh. When an exchange quote expired, the review screen became a dead end without a way to refresh the rate.

Solution

1. Exposed refreshQuote from useSendPayment, which calls quoteApi.refreshQuote(quote.id) and falls back to re-requesting a quote with the current form values.
2. Passed onRefresh={refreshQuote} to <QuoteCard /> in both src/pages/Send.tsx and src/pages/PayRequest.tsx.
3. Added unit tests in src/components/send/QuoteCard.test.tsx verifying the Refresh button renders when onRefresh is provided, triggers the callback upon click, and displays the expired warning when expired.

Verification

• NODE_ENV=test npm test: 28 test suites, 117 tests passing.
• npm run build: Typecheck (tsc) and Vite bundle build pass cleanly with 0 errors.