feat: CSV import and batch reconciliation UI

- Add reconciled_with_id column to transactions (links manual → statement tx)
- CSV import wizard: 4-step modal (upload → map columns → review → done)
  - Handles any bank format via column mapping with localStorage presets
  - Single signed or separate debit/credit column modes
  - Editable preview table before committing
  - Auto-tags all imported rows with 'csv-import'
- Batch reconcile page: shows all unreconciled manual transactions with
  potential statement matches (date ±3 days, amount ±1%) pre-fetched
  - Select matches across multiple rows, apply all at once
  - Copies overrides/tags/splits from manual → statement tx atomically
  - Manual tx marked reconciled (linked), hidden from main transactions view
  - Transactions with no matches shown separately
- Import CSV button on transactions page
- Reconcile nav item in sidebar

src/lib/hooks.ts

@@ -727,6 +727,66 @@ export interface MerchantTxnRow {
   statement_id: number;
 }
 
+// --- CSV Import & Reconcile ---
+
+export function useImportCSV() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: async (body: {
+      bank_name: string;
+      transactions: {
+        date: string; description: string; amount: number; transaction_type: string;
+        merchant_name?: string; foreign_currency_amount?: number; foreign_currency_code?: string; category?: string;
+      }[];
+    }) => {
+      const res = await fetch("/api/import/csv", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify(body),
+      });
+      if (!res.ok) throw new Error((await res.json()).error || "Import failed");
+      return res.json() as Promise<{ inserted: number }>;
+    },
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ["transactions"] });
+      qc.invalidateQueries({ queryKey: ["tags"] });
+      qc.invalidateQueries({ queryKey: ["reconcile-pending"] });
+    },
+  });
+}
+
+import type { ManualTxWithMatches } from "./queries";
+
+export function usePendingReconciliations() {
+  return useQuery<ManualTxWithMatches[]>({
+    queryKey: ["reconcile-pending"],
+    queryFn: async () => {
+      const res = await fetch("/api/reconcile/pending");
+      if (!res.ok) throw new Error("Failed to fetch");
+      return res.json();
+    },
+  });
+}
+
+export function useReconcile() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: async (matches: { manual_id: number; statement_tx_id: number }[]) => {
+      const res = await fetch("/api/transactions/reconcile", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ matches }),
+      });
+      if (!res.ok) throw new Error((await res.json()).error || "Reconcile failed");
+      return res.json() as Promise<{ reconciled: number }>;
+    },
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ["transactions"] });
+      qc.invalidateQueries({ queryKey: ["reconcile-pending"] });
+    },
+  });
+}
+
 export function useMerchantTransactions(merchant: string | null) {
   return useQuery<{ transactions: MerchantTxnRow[] }>({
     queryKey: ["analytics", "merchant-txns", merchant],