Auto-fetch Newbook on date load; add transaction breakdown checklist

- Newbook payments now fetched automatically when a date loads (in
  parallel with the cash up fetch), not just on button click
- Refresh button still available for manual re-fetch
- Transaction breakdown section below reconciliation table: three
  collapsible groups (Reception Manual, Reception Gateway, Restaurant/Bar)
  each showing individual transactions with click-to-tick checkboxes
  for tracking down discrepancies — local state, clears on refresh

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/types.ts

@@ -60,6 +60,20 @@ export interface TillPayment {
   total_value: number
 }
 
+export interface TransactionItem {
+  time: string
+  payment_type: string
+  details: string
+  amount: number
+  is_voided: boolean
+}
+
+export interface TransactionBreakdown {
+  reception_manual:  Record<string, TransactionItem[]>
+  reception_gateway: Record<string, TransactionItem[]>
+  restaurant_bar:    Record<string, TransactionItem[]>
+}
+
 export interface Attachment {
   id: number
   cash_up_id: number