pr.md

Fixes a critical bug where op_no_trust is incorrectly thrown when a recipient lacks a USDC trustline during claimable balance creation.

What we did

1. Removed hasUSDCTrustline check from createClaimableBalance.
2. Added accountExists check before building the transaction to ensure the recipient account exists on the Stellar network, otherwise throwing a clear instructional error.
3. Updated the create route to elegantly translate raw Stellar SDK errors into human-readable messages (op_underfunded, op_low_reserve, etc).
4. Handled op_no_trust in the /claim route to instruct users when they try to claim before adding the trustline: "Recipient must add USDC trustline before claiming. Please add a USDC trustline to your account first."
5. Added a UI hint to the payment page explicitly telling the recipient about the 2-step flow.
6. Added an Auto-claim component tracking available claimable balances via the dashbord and giving users 1-click access.
7. Added tests via Vitest covering all five requested regression scenarios correctly.
8. Added architecture docs in docs/CLAIMABLE_BALANCES.md about the two-step flow.

Closes #241