feat: add inbox-direct supplier invoice creation from inbox items (#558)

* feat: add inbox-direct supplier invoice creation from inbox items

- Implemented `gnubok_create_supplier_invoice_from_inbox` tool in the MCP server for creating supplier invoices directly from inbox items.
- Enhanced the input schema to include `inbox_item_id` and `document_id` for direct booking.
- Added logic to validate inbox items and link documents to journal entries during the commit process.
- Introduced `commitCreateSupplierInvoiceFromInbox` function to handle the creation and linking of supplier invoices.
- Added unit tests to cover various scenarios including happy path, idempotency, error handling, and rollbacks.
- Updated database migration to extend the `pending_operations` table to include the new operation type.

* fix: extend CHECK constraint to include create_supplier_invoice_from_inbox operation

* feat: add validation for financial fields in supplier invoice creation from inbox

types/index.ts

@@ -1445,6 +1445,8 @@ export type PendingOperationType =
   // Stream 1 Phase 1: supplier invoice lifecycle
   | 'approve_supplier_invoice'
   | 'credit_supplier_invoice'
+  // Phase 5: convert an OCR'd inbox item to a leverantörsfaktura + registration JE
+  | 'create_supplier_invoice_from_inbox'
   // Stream 1 Phase 1: invoice operations beyond simple create/send
   | 'credit_invoice'
   | 'convert_invoice'