feat(imports): import history and delete by import

Track imports in DB, show history in Data section, allow deleting
transactions of a specific import instead of clearing all.

shared/src/types/import.ts

@@ -1,3 +1,16 @@
+/** Import record from imports table (for import history) */
+export interface Import {
+  id: number;
+  importedAt: string;
+  accountId: number | null;
+  accountAlias: string | null;
+  bank: string;
+  accountNumberMasked: string;
+  importedCount: number;
+  duplicatesSkipped: number;
+  totalInFile: number;
+}
+
 /** JSON 1.0 statement file — the shape accepted by POST /api/import/statement */
 export interface StatementFile {
   schemaVersion: '1.0';

shared/src/types/index.ts

@@ -37,6 +37,7 @@ export type {
   StatementHeader,
   StatementTransaction,
   ImportStatementResponse,
+  Import,
 } from './import';
 
 export type {