Ledger section with sub-tabs: overview (money held/owed, payouts by status, and
a reconciliation warning card), payouts + transactions lists, per-seller balances
list, and a per-seller detail showing recorded vs derived balance + discrepancy,
bank accounts and payout history. Enabled the Ledger nav item.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>