Redesign the setup flow and consolidate the CSS into one primitives layer

Onboarding asks explicitly for one or two parents and shows one card per
parent for balances; the balance form is per parent with inline
validation; the partner can be filled from the FK deduction or added
from it. Settings and Dashboard reuse the same form.

CSS: bare buttons carry no colour any more; buttons, cards, choice
cards, fields, alerts, badges, eyebrow and modal chrome are defined once
in primitives.css. Media queries live only in responsive.css. A style
guard test blocks hex, !important and stray media queries. Bilingual
fixes: calendar selects size by content, header no longer wraps. Vitest
is capped at four workers.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

frontend/tests/fixtures/scraper.ts

@@ -10,7 +10,8 @@
  */
 
 import type { startScraperSession } from '@/services/api'
-import type { PollResponse } from '@/hooks/useScraperFetch'
+import type { PollResponse, RawPartnerDeduction } from '@/hooks/useScraperFetch'
+import type { PartnerDeduction } from '@/types'
 
 export type ScraperSessionStartResponse = Awaited<ReturnType<typeof startScraperSession>>
 
@@ -35,3 +36,30 @@ export function makeScraperSessionStartResponse(
 export function makePollResponse(overrides: Partial<PollResponse> = {}): PollResponse {
   return { status: 'launching', ...overrides }
 }
+
+/** Raw (snake_case) wire shape of `partner_deduction`, as it arrives nested
+ * inside a poll response — pair with `makePartnerDeduction` for the
+ * camelCase value `useScraperFetch` derives from it. */
+export function makeRawPartnerDeduction(
+  overrides: Partial<RawPartnerDeduction> = {},
+): RawPartnerDeduction {
+  return {
+    total_days: 240,
+    days_left: 140,
+    sjukpenning_left: 100,
+    lagsta_niva_left: 40,
+    dubbeldagar_left: 20,
+    ...overrides,
+  }
+}
+
+export function makePartnerDeduction(overrides: Partial<PartnerDeduction> = {}): PartnerDeduction {
+  return {
+    totalDays: 240,
+    daysLeft: 140,
+    sjukpenningLeft: 100,
+    lagstaNivaLeft: 40,
+    dubbeldagarLeft: 20,
+    ...overrides,
+  }
+}