Fix/invoice delivery and payment accounts (#1116)

* fix: reconcile annual reports with final closing entries

* test: cover annual report depreciation and VAT balances

* Merge remote-tracking branch 'origin/main' into fix/usr-fdbck-ch

* fix: show exact invoice delivery details

* fix: use currency account in invoice emails

* fix: address invoice delivery review feedback

* fix: harden invoice delivery and payment accounts

* test: assert RLS-denied zero-row updates

* fix: close remaining invoice compliance gaps

* fix: harden invoice archive authorization

* fix: close invoice delivery review findings

* fix: verify delivery finalization results

* fix: cap combined invoice email recipients

* fix: close final invoice compliance findings

* fix: prevent stale payment account saves

* test: prove invoice delivery isolation

* fix: close invoice privacy review findings

* test: normalize delivery retention dates

lib/errors/structured-errors.ts

@@ -885,11 +885,25 @@ const INVOICE: Record<string, StructuredErrorEntry> = {
     message_en: 'Customer has no email address.',
     remediation: { description: 'Add an email address on the customer record before sending.' },
   },
+  INVOICE_SEND_TOO_MANY_RECIPIENTS: {
+    httpStatus: 400,
+    message_sv: 'Ett fakturautskick får ha högst 20 mottagare totalt.',
+    message_en: 'An invoice email may have at most 20 recipients in total.',
+    remediation: { description: 'Remove CC or BCC recipients before sending the invoice.' },
+  },
   INVOICE_SEND_COMPANY_SETTINGS_MISSING: {
     httpStatus: 404,
     message_sv: 'Företagsinställningar saknas.',
     message_en: 'Company settings are missing.',
   },
+  INVOICE_SEND_PAYMENT_ACCOUNT_MISSING: {
+    httpStatus: 400,
+    message_sv: 'Fakturan saknar ett betalningskonto för vald valuta. Lägg till kontot under Fakturering innan du skapar PDF-filen eller skickar fakturan.',
+    message_en: 'The invoice has no payment account for its currency. Add the account under Invoicing before generating the PDF or sending the invoice.',
+    remediation: {
+      description: 'Lägg till ett betalningskonto med IBAN för fakturans valuta under Fakturering.',
+    },
+  },
   INVOICE_SEND_NUMBER_ASSIGN_FAILED: {
     httpStatus: 500,
     message_sv: 'Kunde inte tilldela fakturanummer.',
@@ -2848,8 +2862,8 @@ const BOLAGSVERKET: Record<string, StructuredErrorEntry> = {
   },
   ARSREDOVISNING_INCOMPLETE: {
     httpStatus: 409,
-    message_sv: 'Årsredovisningen har blockerande kontrollfel och kan inte låsas ännu.',
-    message_en: 'The annual report has blocking validation errors and cannot be finalized yet.',
+    message_sv: 'Årsredovisningen har blockerande kontrollfel och kan inte versionssparas ännu.',
+    message_en: 'The annual report has blocking validation errors and cannot be versioned yet.',
     retryable: false,
   },
   ARSREDOVISNING_VERSION_NOT_SIGNABLE: {