style(ui): system-wide UX/UI polish pass — design-system conformance + copy cleanup (#835)

* style(ui): system-wide UX/UI polish pass — design-system conformance + copy cleanup

Multi-agent scan of all 404 UI files against the locked design system, then
141 verified surgical fixes across 109 files (net -32 lines):

- Remove forbidden elevation/motion: shadow-* and rounded-xl on cards, active:scale
  bounce, hover:shadow on list items, transition-all -> transition-colors.
- Drop font-medium from single-weight Hedvig display headings/numerals.
- Replace raw rainbow Tailwind status colors with Badge variants / brand tokens /
  neutral surfaces (achromatic chrome, semantic colors stay data-only).
- Route raw dates through formatDate(), hand-rolled currency through formatCurrency(),
  add tabular-nums to financial figures; text-gray-* -> text-foreground tokens.
- Swap hand-rolled skeletons for the Skeleton primitive; off-scale spacing -> token scale.
- Fix copy: mislabeled "Leverantörsfakturor" -> "Utgifter" on bank-import outflow total,
  collapse no-op identical-branch ternaries, broken Swedish diacritics (mojibake),
  correct mismatch-password toast, correct supplier currency-field label.
- Remove PII-leaking debug console.log on register, stray console.logs.

Verified: tsc clean on all changed files, eslint clean, production build passes.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(auth): sanitize residual error logs in register flow

Follow-up to PR review (compliance swarm V16 / GDPR Art.5(1)(f)): the
remaining console.error calls in the register flow passed raw error
objects, which Supabase may populate with PII (email) in nested fields.
Log only sanitized message strings instead.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

components/invoices/InvoiceEditor.tsx

@@ -1113,7 +1113,7 @@ export default function InvoiceEditor(props: InvoiceEditorProps = { mode: 'creat
           <ArrowLeft className="h-5 w-5" />
         </Button>
         <div className="flex-1 min-w-0">
-          <h1 className="font-display text-2xl md:text-3xl font-medium tracking-tight">
+          <h1 className="font-display text-2xl md:text-3xl tracking-tight">
             {titleText}
             {numberPreview && !isSelfBilled && (
               <span className="ml-2 text-muted-foreground tabular-nums text-xl md:text-2xl">

components/invoices/InvoiceReviewContent.tsx

@@ -4,7 +4,7 @@ import { useTranslations } from 'next-intl'
 import { CalendarClock } from 'lucide-react'
 import { Badge } from '@/components/ui/badge'
 import { Separator } from '@/components/ui/separator'
-import { formatCurrency } from '@/lib/utils'
+import { formatCurrency, formatDate } from '@/lib/utils'
 import { getDisplayTotal } from '@/lib/invoices/rounding'
 import { itemHasAccrual } from '@/lib/bookkeeping/accruals/account-suggestions'
 import type { Customer, Currency } from '@/types'
@@ -108,11 +108,11 @@ export function InvoiceReviewContent({
       <div className="grid grid-cols-1 sm:grid-cols-2 gap-4 text-sm">
         <div>
           <span className="text-muted-foreground">{t('invoice_date')}</span>
-          <p className="font-medium">{invoiceDate}</p>
+          <p className="font-medium">{invoiceDate ? formatDate(invoiceDate) : ''}</p>
         </div>
         <div>
           <span className="text-muted-foreground">{t('due_date')}</span>
-          <p className="font-medium">{dueDate}</p>
+          <p className="font-medium">{dueDate ? formatDate(dueDate) : ''}</p>
         </div>
       </div>