CSV Upload & Duplicate Batch for Payroll

[Huygon764]

Problem: Users must manually select contacts and fill amounts one by one for batch payments. For recurring payroll, there is no way to reuse a previous batch.

Expected behavior:

• CSV Upload — add an upload button in the Create Batch flow. Parse CSV (expected columns: address, amount, token), validate each row (valid address format, amount is a number, token is supported). On success, skip step 1 (Choose Contact) and populate step 2 (Add to Batch) with parsed data. On invalid rows, show toast with error details. User can edit before submitting.

• Duplicate Batch — add a "Duplicate" button on batch transaction rows in the Dashboard. Clicking it opens the Create Batch modal directly at step 2 (Add to Batch) with recipients and tokens pre-filled from the previous batch. Amounts are editable. Submits through the same flow (step 3 → Transaction Summary → Submit batch).

Notes:

• Both features reuse existing step 2 and step 3 of the modal — no new steps needed.
• Depends on designer task for UI placement and layout.