Tutorial 03 step 5: "Next step" doesn't unlock after send to Test Wallet

### Packages versions

N/A — web playground at playground.miden.xyz (Testnet), Chrome

### Bug description

In tutorial 03 ("Connect wallet and sign transactions"), step 5 of 6 asks to submit a send transaction to the recipient wallet.

What I did: connected Miden Wallet (public account), minted 100 MDN via the tutorial button, consumed the note, then submitted send transactions: 50 MDN to another account I own and 2x10 MDN to the imported Test Wallet (mtst1az7el72...yycr4h99). All transactions were confirmed — my account nonce increased to 3 and balances updated correctly.

Expected: the "Next step" button unlocks after the send transaction is confirmed.

Actual: "Next step" stays disabled, even after a page refresh.

Possibly related: after a page reload, the imported Test Wallet disappeared from the Accounts list and I had to re-import it manually.

### How can this be reproduced?

1. Open tutorial 03 "Connect wallet and sign transactions" on playground.miden.xyz (Testnet)
2. Connect a public Miden Wallet account, mint 100 MDN (step 2), consume the note (step 3)
3. On step 4, copy the Test Wallet address, import it via "Create new account" -> "Import account"
4. On step 5, create a "New send transaction": target = Test Wallet, asset = MDN, amount = 10, submit and sign
5. Wait for the tx to confirm (nonce increases, balance updates), refresh the page
6. "Next step" remains disabled

Note: reloading the page also removes the imported Test Wallet from the Accounts list.

### Relevant log output

```shell

```

The issue is in the tutorial flow logic, likely in the frontend component that checks for transaction confirmation to enable the 'Next step' button. Start by examining the tutorial 03 step 5 implementation in the frontend code, possibly in a React component or state management file. Look for the condition that unlocks the button, which may depend on verifying a transaction to the specific Test Wallet address. Also check the account import persistence to see why the Test Wallet disappears on refresh. Run the playground locally and reproduce the bug to understand the state transitions.

索引モデルが issue の本文から書いたものです。