fix(customers): personnummer guard + personal_number on v1 + payment terms from settings (#1724)

* fix(customers): stop personnummer landing unmasked as org_number, persist personal_number on v1, default payment terms from settings

Closes #1707. Closes #1708.

Personnummer (#1707, Discord kalletoxic):
- CreateCustomerSchema rejects an org_number shaped like a Swedish
  personal identity number on business customer_types. Only
  customer_type=individual rows are masked in lists, so accepting one
  stored an unmasked personal identifier (GDPR art. 5.1 c). The shape
  check uses the month-position rule (legal-entity orgnr always
  carries >= 20), so real orgnr can never false-positive.
- The v1 create, v1 PATCH and bulk-create endpoints accepted
  personal_number through the shared schema but silently dropped it.
  They now store it encrypted, expose it masked (********-1234) on the
  single-customer surfaces, and treat the masked form as unchanged,
  mirroring the internal routes.
- Route-level guards on both PATCH routes (new 400
  CUSTOMER_ORG_NUMBER_IS_PERSONAL) plus a client-side message in
  CustomerForm (sv + en).

Payment terms (#1708, Discord kalletoxic):
- New resolveDefaultPaymentTerms: provided value, else
  company_settings.invoice_default_days, else 30. Wired into the UI
  new-customer dialog, the internal POST, v1 create (incl. dry-run),
  bulk-create and the MCP staged create_customer.

apiskill regenerated; no migrations.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* docs: record what the CI build OOM actually was

main raised the build heap to 8192 in parallel with this branch, so the
fix itself is already in and this keeps it untouched. What was missing
is the diagnosis.

Measured with tsc --noEmit --extendedDiagnostics, type-checking the repo
needs 4 192 550 K at 506d030b and 4 187 096 K on this branch, 5 MB less
and 0.26% more instantiations. So the ceiling is the type-check pass at
steady state against Node 20's ~4 GB default old-space, not bundle
growth and not any single PR. Worth writing down so the next person who
sees "Ineffective mark-compacts near heap limit" does not go looking for
it in their own diff.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

lib/pending-operations/commit.ts

@@ -25,6 +25,8 @@ import {
 import { roundOre } from '@/lib/money'
 import { getErrorMessage } from '@/lib/errors/get-error-message'
 import { validateVatNumber } from '@/lib/vat/vies-client'
+import { looksLikeSwedishPersonalNumber } from '@/lib/customers/personal-number-shape'
+import { resolveDefaultPaymentTerms } from '@/lib/customers/default-payment-terms'
 import {
   normalizeVatRateToDecimal,
   normalizeVatRateToFraction,
@@ -354,6 +356,30 @@ async function commitCreateCustomer(
     return { error: 'customer_number must be a string of at most 32 characters', status: 400 }
   }
 
+  // Same GDPR guard as CreateCustomerSchema: identifiers are only masked on
+  // customer_type='individual' rows, so a personnummer stored as a business
+  // org_number would be shown unmasked everywhere.
+  const orgNumber = (params.org_number as string) || null
+  if (
+    orgNumber &&
+    params.customer_type !== 'individual' &&
+    looksLikeSwedishPersonalNumber(orgNumber)
+  ) {
+    return {
+      error:
+        'org_number ser ut som ett personnummer. Skapa kunden som privatperson '
+        + '(customer_type=individual) i stället, så maskeras numret i listor.',
+      status: 400,
+    }
+  }
+
+  // Unset payment terms follow the company's own default, not a hardcoded 30.
+  const defaultPaymentTerms = await resolveDefaultPaymentTerms(
+    supabase,
+    companyId,
+    typeof params.payment_terms === 'number' ? params.payment_terms : undefined,
+  )
+
   const { data, error } = await supabase
     .from('customers')
     .insert({
@@ -363,9 +389,9 @@ async function commitCreateCustomer(
       customer_type: params.customer_type as string,
       customer_number: customerNumber || null,
       email: (params.email as string) || null,
-      org_number: (params.org_number as string) || null,
+      org_number: orgNumber,
       vat_number: (params.vat_number as string) || null,
-      default_payment_terms: (params.payment_terms as number) || 30,
+      default_payment_terms: defaultPaymentTerms,
       address_line1: (params.address as string) || null,
       postal_code: (params.postal_code as string) || null,
       city: (params.city as string) || null,