refactor(ui): design-system consistency pass over dense pages + i18n de-bloat (#961)

* refactor(ui): normalize dense pages to the locked design system

Sweep of the info-dense surfaces against .claude/rules/design.md; no
behavior changes, classNames and primitive adoption only.

- Replace hand-rolled h1s with PageHeader (import, suppliers, kpi,
  salary/employees, skattekonto, settings layout) and drop the one
  double title (SalarySettingsContent under the settings h1)
- Replace hand-rolled empty states with EmptyState (skattekonto,
  banking/api-keys/oauth/counterparty settings) and hand-rolled
  pulse divs with Skeleton (deadlines, report view loaders)
- Remove semantic colors used as chrome: amber/emerald banners in
  AGIPanel and SkatteverketPanel, success/warning tints in
  kassaflodesanalys, arsredovisning and import become neutral
  surfaces with the tint kept on the icon only
- Full-opacity borders everywhere (border-border/30-60,
  border-destructive/20-40, border-foreground/30, text-destructive/80)
- Snap off-scale spacing (p-5 to p-6, p-2.5 to p-3, gap/mt-x.5 to
  scale values); KPI metric tiles p-6 to p-4 per the tile rule
- Remove the mobile Select that duplicated the invoices status Tabs
  (TabsList already scrolls horizontally); single Tabs now serves
  both breakpoints
- supplier-invoices: shared formatCurrency instead of a local
  formatAmount helper; skattekonto: formatDate/formatDateLong/
  formatDateTime instead of raw dates and toLocaleString
- arsredovisning flerarsoversikt converted to the Table primitive
  with right-aligned tabular-nums cells
- Settings: CardTitle text-base on section cards, one heading idiom
  in AccountSettingsContent, h3 to h2 in CompanyProfileView

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

* refactor(i18n): trim text bloat and fix an untranslated sv string

- Fix invoice_credit.create_failed_fallback: sv catalog carried the
  English "Failed to create credit note"; now "Kunde inte skapa
  kreditfaktura". Translate new_user_checklist.step3_title in en
- Drop descriptions that paraphrase their own title (design.md
  forbidden pattern): invoice_detail.credited_description,
  invoice_credit.original_card_description, invoice_editor
  customer/notes card descriptions (keys deleted from both
  catalogs, zero remaining usages); the transaction booking
  DialogDescription becomes sr-only so screen readers keep it
- Trim redundant sentences from settings_salary.info_payroll_scope,
  settings_backup.intro, ext_cloud_backup_long_description,
  settings.name_description, salary_payments.open_payments_note and
  shorten invoice_credit.reason_card_description; statutory BFL/tax
  prose untouched
- Normalize toast punctuation (dimensions/self_billing
  created_description lose the trailing period like their siblings)
- common.delete "Radera" to "Ta bort" (zero live call sites; Radera
  stays reserved for irreversible account/company deletion)

Catalogs verified key-identical (4795 keys each) and JSON-parseable.

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

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

components/transactions/TransactionBookingDialog.tsx

@@ -252,7 +252,7 @@ export default function TransactionBookingDialog({
       <DialogContent className="max-w-6xl max-h-[90vh] overflow-y-auto">
         <DialogHeader>
           <DialogTitle>{t('title')}</DialogTitle>
-          <DialogDescription>
+          <DialogDescription className="sr-only">
             {t('description')}
           </DialogDescription>
         </DialogHeader>