fix: BankID fallback, bank import fixes, account deletion (#216)

* fix: BankID graceful fallback, bank import fixes, and account deletion

- BankID: surface service_unavailable state in login/register with password
  fallback messaging; structured error codes in tic extension; poll failure
  counter in BankIdAuth avoids infinite retry when TIC API is down.
- Transactions: allow deleting unbooked bank-synced and imported transactions
  (only posted entries remain protected); detect reconnect duplicates by also
  checking unbooked bank-synced rows in content-based dedup.
- Enable Banking: key external_id by account iban/uid instead of connection id
  so reconnects don't create duplicates.
- Bank import: detect SEB privatbanken CSV variant (Bokföringsdatum /
  Valutadatum headers) via regex.
- Banking settings: replace full-screen sync loader with toast notifications.
- delete_user_account: raise statement_timeout, pre-clear NO ACTION FK
  references, and disable audit/immutability triggers during CASCADE.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: address Greptile review — ingest dedup scoping and migration EXCEPTION handler

- ingest: split buildExistingTransactionMap into two maps. Booked rows
  (any source) remain consumed by any incoming raw transaction, but
  unbooked enable_banking slots are only consumed when the incoming raw
  transaction is also enable_banking. This preserves reconnect dedup
  while preventing false positives where a pending bank-synced row
  silently blocks a legitimately separate CSV row with the same
  date/amount.
- delete_user_account: add EXCEPTION WHEN OTHERS handler that re-enables
  every legally required enforcement trigger before re-raising. Postgres
  transactional DDL already rolls back on abort, but the explicit guard
  makes the intent unambiguous and covers sub-transaction edge cases so
  enforcement triggers are never left disabled.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

extensions/general/enable-banking/lib/__tests__/sync.test.ts

@@ -163,7 +163,7 @@ describe('syncAccountTransactions', () => {
     expect(mockIngest).toHaveBeenCalledTimes(1)
     const rawTxns = mockIngest.mock.calls[0][3]
     expect(rawTxns).toHaveLength(1)
-    expect(rawTxns[0].external_id).toBe('conn-1_tx-500')
+    expect(rawTxns[0].external_id).toBe('eb_acc-uid-1_tx-500')
     expect(rawTxns[0].import_source).toBe('enable_banking')
   })
 })

extensions/general/enable-banking/lib/sync.ts

@@ -76,7 +76,7 @@ export async function syncAccountTransactions(
     description: tx.description || tx.counterparty_name || 'Unknown',
     amount: tx.amount,
     currency: tx.currency || account.currency,
-    external_id: `${connectionId}_${tx.id}`,
+    external_id: `eb_${account.iban || account.uid}_${tx.id}`,
     mcc_code: tx.merchant_category_code ? parseInt(tx.merchant_category_code, 10) : null,
     merchant_name: tx.counterparty_name || null,
     reference: tx.reference || null,