feat: transaction categorization UX improvements and description matching

Add journal entry preview, human-readable account names, auto-apply VAT,
fallback template suggestions, example prompts, invoice match comparison,
and batch result feedback. Also includes user-description-match extension,
describe/batch-describe API routes, improved AI categorization with multi-
suggestion support, and template embedding search.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

types/index.ts

@@ -13,6 +13,10 @@ export type TransactionCategory =
   | 'expense_marketing'
   | 'expense_professional_services'
   | 'expense_education'
+  | 'expense_representation'
+  | 'expense_consumables'
+  | 'expense_vehicle'
+  | 'expense_telecom'
   | 'expense_bank_fees'
   | 'expense_card_fees'
   | 'expense_currency_exchange'
@@ -899,6 +903,10 @@ export interface MappingRule {
   // Capitalization
   capitalization_threshold: number | null
   capitalized_debit_account: string | null
+  // Source tracking
+  source: 'auto' | 'user_description' | 'system'
+  user_description: string | null
+  template_id: string | null
   // Meta
   is_active: boolean
   created_at: string