ok for now

lib/utils/look_ahead.dart

@@ -0,0 +1,105 @@
+/// Project future balances from recurring transactions.
+library;
+
+import '../models/bank.dart';
+import '../models/transaction_meta.dart';
+import 'tx_calendar.dart';
+
+/// One monthly recurring item used for look-ahead forecasts.
+class RecurringItem {
+  const RecurringItem({
+    required this.description,
+    required this.amount,
+    required this.currency,
+    required this.dayOfMonth,
+    required this.category,
+  });
+
+  final String description;
+  final double amount;
+  final String currency;
+  final int dayOfMonth;
+  final TxCategory category;
+}
+
+/// Build unique recurring templates from annotated transactions.
+List<RecurringItem> recurringItemsFrom({
+  required List<BankTransaction> transactions,
+  required TxMeta Function(BankTransaction tx) metaFor,
+}) {
+  final latestByExact = <String, BankTransaction>{};
+  for (final tx in transactions) {
+    final meta = metaFor(tx);
+    if (!meta.recurring) continue;
+    final existing = latestByExact[tx.exactKey];
+    if (existing == null) {
+      latestByExact[tx.exactKey] = tx;
+      continue;
+    }
+    final existingDate = DateTime.tryParse(existing.date);
+    final nextDate = DateTime.tryParse(tx.date);
+    if (existingDate == null ||
+        (nextDate != null && nextDate.isAfter(existingDate))) {
+      latestByExact[tx.exactKey] = tx;
+    }
+  }
+
+  return [
+    for (final tx in latestByExact.values)
+      RecurringItem(
+        description: tx.description,
+        amount: tx.amount,
+        currency: tx.currency,
+        dayOfMonth: (DateTime.tryParse(tx.date)?.day ?? 1).clamp(1, 28),
+        category: metaFor(tx).category,
+      ),
+  ];
+}
+
+/// Occurrences of [items] with dates in `(from, to]` (exclusive start, inclusive end).
+List<({RecurringItem item, DateTime date})> projectedOccurrences({
+  required List<RecurringItem> items,
+  required DateTime from,
+  required DateTime to,
+}) {
+  final start = dateOnly(from);
+  final end = dateOnly(to);
+  if (!end.isAfter(start)) return const [];
+
+  final out = <({RecurringItem item, DateTime date})>[];
+  var cursor = monthStart(start);
+  final lastMonth = monthStart(end);
+
+  while (!cursor.isAfter(lastMonth)) {
+    final daysInMonth = DateTime(cursor.year, cursor.month + 1, 0).day;
+    for (final item in items) {
+      final day = item.dayOfMonth.clamp(1, daysInMonth);
+      final date = DateTime(cursor.year, cursor.month, day);
+      if (date.isAfter(start) && !date.isAfter(end)) {
+        out.add((item: item, date: date));
+      }
+    }
+    cursor = addMonths(cursor, 1);
+  }
+
+  out.sort((a, b) => a.date.compareTo(b.date));
+  return out;
+}
+
+/// Current balance plus projected recurring amounts through [throughDate].
+double predictBalance({
+  required double currentBalance,
+  required DateTime from,
+  required DateTime throughDate,
+  required List<RecurringItem> items,
+}) {
+  final projected = projectedOccurrences(
+    items: items,
+    from: from,
+    to: throughDate,
+  );
+  return projected.fold<double>(
+    currentBalance,
+    (sum, row) => sum + row.item.amount,
+  );
+}