feat(invoice-inbox): receipt-aware extraction + OCR pipeline fixes (#1331)

Receipts and invoices were extracted through one invoice-shaped prompt
with no document classification. The extractor now also returns
documentKind, payment method (+ card last4), purchaseTime,
merchantCategory and legibility, validated with .catch(null) so a
hallucinated label degrades to unknown instead of sinking the parse.
The FieldsRail shows type and payment method above the editable fields.

Pipeline fixes, all verified against real failure paths:
- PDFs >3 pages: extract from a pdf-lib slice of the first 3 pages
  instead of skipping entirely (issue #553 gate); truncation recorded
  in extracted_data.pages and shown in the UI.
- Oversized images (>4 MB, over Bedrock's 5 MB cap): downscale to
  <=2000px JPEG via sharp before base64, instead of erroring to an
  empty result.
- HEIC/HEIF: attempt sharp transcode to JPEG; when libvips lacks HEIF
  (prebuilt binaries), fall through to today's behavior but show an
  explicit hint instead of silently blank fields.
- Oresavrundning: prompt rule + totals.roundingAmount so receipt totals
  reconcile with subtotal+VAT for exact-amount transaction matching.
- retry-extraction overwrites extracted_data wholesale: a confirm now
  guards against silently destroying manual field edits.

Deliberately NOT added: retry-on-transient-Bedrock-error; the SDK
already retries twice by default (maxRetries=2).

Co-authored-by: Jakob Wennberg <jakob.wennberg@gmail.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

types/index.ts

@@ -3628,7 +3628,32 @@ export interface IngestResult {
 
 // ── Invoice extraction (used by invoice-inbox extension and core utils) ──
 
+export type ExtractedDocumentKind =
+  | 'receipt'
+  | 'supplier_invoice'
+  | 'government_letter'
+  | 'other'
+export type ExtractedPaymentMethod = 'card' | 'swish' | 'cash' | 'invoice' | 'other'
+export type ExtractedMerchantCategory =
+  | 'restaurant'
+  | 'cafe'
+  | 'taxi'
+  | 'parking'
+  | 'fuel'
+  | 'grocery'
+  | 'hotel'
+  | 'other'
+export type ExtractedLegibility = 'good' | 'partial' | 'unreadable'
+
 export interface InvoiceExtractionResult {
+  // Classification fields (2026-08): optional because extractions stored
+  // before they existed lack them. They route UI emphasis and clarifying
+  // questions only: never bookings.
+  documentKind?: ExtractedDocumentKind | null
+  merchantCategory?: ExtractedMerchantCategory | null
+  legibility?: ExtractedLegibility | null
+  purchaseTime?: string | null
+  payment?: { method: ExtractedPaymentMethod | null; cardLast4: string | null } | null
   supplier: {
     name: string | null
     orgNumber: string | null
@@ -3654,10 +3679,15 @@ export interface InvoiceExtractionResult {
     subtotal: number | null
     vatAmount: number | null
     total: number | null
+    // Öresavrundning line on Swedish receipts; negative when rounded down.
+    roundingAmount?: number | null
   }
   vatBreakdown: VatBreakdownItem[]
   confidence: number
   suggestedTemplateId?: string
+  // Set by the caller (not the model) when a long PDF was sliced before
+  // extraction: fields were read from the first `analyzed` of `total` pages.
+  pages?: { total: number; analyzed: number }
 }
 
 export interface ExtractedInvoiceLineItem {