fix(a11y): add accessible aria-labels to BatchForm recipient inputs (#54)

[ghzhost]

Closes #54

Problem

In BatchForm, the per-recipient destination address and amount Input fields were passed without label or aria-label props. Because Input only derives an id and <label> when label is provided, screen-reader users encountered inputs with no accessible name.

Solution

• Added explicit aria-label={Recipient ${index + 1} address} and aria-label={Recipient ${index + 1} amount} to each recipient row's inputs in BatchForm.tsx.
• Updated BatchForm.test.tsx to query elements by their accessible role and name (getByRole('textbox', { name: /recipient 1 address/i }), getByRole('spinbutton', { name: /recipient 1 amount/i })).

Verification

• Tested locally with NODE_ENV=test npm test: 27 test files passed (113 tests).