fix(import): persist source files in IndexedDB so attach survives a reload

The source document was only kept in memory on the background task, so a page reload during the (now always-LLM ~25s) parse lost it and the booking saved without its file. Store the uploaded files in IndexedDB keyed by job id; the review loads them from there when the in-memory copy is gone, and a 1h TTL prunes abandoned imports.

client/src/components/Planner/BookingImportModal.tsx

@@ -4,6 +4,7 @@ import { Upload, X } from 'lucide-react'
 import { useTranslation } from '../../i18n'
 import { reservationsApi, healthApi } from '../../api/client'
 import { useBackgroundTasksStore } from '../../store/backgroundTasksStore'
+import { saveImportFiles } from '../../db/offlineDb'
 
 interface BookingImportModalProps {
   isOpen: boolean
@@ -96,7 +97,9 @@ export default function BookingImportModal({ isOpen, onClose, tripId }: BookingI
     try {
       const mode = aiParsing ? 'fallback-on-empty' : 'no-ai'
       const { jobId } = await reservationsApi.importBookingAsync(tripId, files, mode)
-      // Keep the uploaded files so the review can attach each source document to its booking.
+      // Keep the uploaded files so the review can attach each source document to its booking —
+      // in memory for the immediate path, and in IndexedDB so it survives a reload mid-parse.
+      await saveImportFiles(jobId, files)
       addTask({ id: jobId, tripId: String(tripId), label: files.map((f) => f.name).join(', '), total: files.length, files })
       handleClose()
     } catch (err: any) {