feat: implement skattekonto drift detection and alerting (#525)

* feat: implement skattekonto drift detection and alerting

- Add skattekonto drift computation logic to compare Skatteverket's saldo with GL 1630 sum.
- Implement alerting mechanism for significant drift changes, with throttling to prevent alert spamming.
- Introduce database functions to sum GL 1630 entries and list unbooked skattekonto rows.

feat: create own account transfer detection

- Develop logic to detect transfers between a company's own cash accounts based on counterparty IBAN.
- Implement tests to validate detection logic under various scenarios, including matching and non-matching IBANs.

feat: establish cash accounts as a first-class entity

- Create cash_accounts table to manage routable cash accounts, replacing ad-hoc JSONB structures.
- Implement functions for listing, upserting, and managing cash accounts, including primary account designation.

feat: enhance GL line reconciliation functionality

- Modify get_unlinked_1930_lines RPC to accept any account number for reconciliation, improving flexibility for different currencies.
- Update related functions to ensure compatibility with the new cash_accounts structure.

feat: capture counterparty IBAN in transactions

- Add counterparty_iban column to transactions table to facilitate intra-account transfer detection.
- Create index for efficient lookups based on counterparty IBAN.

* feat: Enhance cash account handling and reconciliation processes

- Updated reconciliation routes to enforce cash account validation for all account numbers, including '1930'.
- Improved error handling for unknown cash accounts in reconciliation status and unmatched entries routes.
- Changed CashAccountSelector to use sessionStorage instead of localStorage for better data privacy.
- Fixed mapping for employer payroll taxes to route to the correct account (2730 instead of 2731).
- Added safety checks for company IDs in the guessCounterAccount function to prevent injection vulnerabilities.
- Introduced atomic RPC for setting primary cash accounts to avoid intermediate states during updates.
- Seeded default cash accounts for new companies to ensure reconciliation routes are accessible from day one.
- Updated email notifications for drift detection to avoid exposing sensitive financial data.
- Enhanced bank reconciliation logic to handle multi-currency transactions correctly.
- Renamed and updated tests to reflect changes in the underlying RPCs and ensure accurate coverage.
- Migrated existing cash account rules to correct mappings in compliance with Swedish accounting standards.

lib/extensions/context-factory.ts

@@ -2,6 +2,7 @@ import type { SupabaseClient } from '@supabase/supabase-js'
 import type { CoreEvent } from '@/lib/events/types'
 import { eventBus } from '@/lib/events/bus'
 import { ingestTransactions } from '@/lib/transactions/ingest'
+import { listForCompany as cashAccountsList, getPrimary as cashAccountsGetPrimary } from '@/lib/cash-accounts/service'
 import { createLogger } from '@/lib/logger'
 import type {
   ExtensionContext,
@@ -116,6 +117,9 @@ function createStorage(supabase: SupabaseClient): ExtensionStorage {
 function createServices(): ExtensionServices {
   return {
     ingestTransactions,
+    getCashAccounts: (supabase, companyId, opts) => cashAccountsList(supabase, companyId, opts),
+    getPrimaryCashAccount: (supabase, companyId, currency) =>
+      cashAccountsGetPrimary(supabase, companyId, currency),
   }
 }
 

lib/extensions/types.ts

@@ -1,6 +1,12 @@
 import type { SupabaseClient } from '@supabase/supabase-js'
 import type { CoreEvent, CoreEventType } from '@/lib/events/types'
-import type { EntityType, RawTransaction, IngestResult, IngestOptions } from '@/types'
+import type {
+  CashAccount,
+  EntityType,
+  IngestOptions,
+  IngestResult,
+  RawTransaction,
+} from '@/types'
 
 // ============================================================
 // Extension Marketplace Types
@@ -167,6 +173,18 @@ export interface ExtensionStorage {
 /** Core services exposed to extensions */
 export interface ExtensionServices {
   ingestTransactions(supabase: SupabaseClient, companyId: string, userId: string, raw: RawTransaction[], options?: IngestOptions): Promise<IngestResult>
+  /**
+   * List a company's cash accounts (cash_accounts table). Replaces ad-hoc reads
+   * of bank_connections.accounts_data for routing decisions. Returns rows
+   * sorted by `is_primary DESC, ledger_account ASC`.
+   */
+  getCashAccounts(supabase: SupabaseClient, companyId: string, opts?: { enabledOnly?: boolean }): Promise<CashAccount[]>
+  /**
+   * Primary cash account for a company, optionally filtered by currency.
+   * Falls back to the global primary when no currency-specific row matches.
+   * Used by the skattekonto __PRIMARY_SEK__ sentinel and transfer-pairing.
+   */
+  getPrimaryCashAccount(supabase: SupabaseClient, companyId: string, currency?: string): Promise<CashAccount | null>
 }
 
 /** Context passed to extension lifecycle hooks and event handlers */