feat(plan): ilk dönem sihirbazı (dönem, gelir, gider, birikim, bütçe)

- /plan/donem-ac?adim=1..5: her adım hemen kaydedilir, adım adreste
- Panel ve Plan'da açık dönem yoksa "Dönemi başlat" kartı
- MoneyInput (sayısal klavye, Türkçe biçim), moneyText/toKurus, period-dates
- lib/periods.ts: dönem, plan kalemi, özet, bütçe ve öneri kancaları
- SummaryTiles, PageLoading/PageError; 13 yeni vitest

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/src/router.tsx

@@ -9,6 +9,7 @@ import { DesignPreview } from '@/features/dev/design-preview'
 import { NotFoundPage } from '@/features/errors/not-found-page'
 import { LedgerPage } from '@/features/ledger/page'
 import { MorePage } from '@/features/more/page'
+import { PeriodWizardPage } from '@/features/period-wizard/page'
 import { PlanningPage } from '@/features/planning/page'
 import { ReportsPage } from '@/features/reports/page'
 import { ReviewPage } from '@/features/review/page'
@@ -34,6 +35,7 @@ const routes: RouteObject[] = [
           { index: true, element: <DashboardPage /> },
           { path: paths.ledger, element: <LedgerPage /> },
           { path: paths.planning, element: <PlanningPage /> },
+          { path: paths.periodWizard, element: <PeriodWizardPage /> },
           { path: paths.savings, element: <SavingsPage /> },
           { path: paths.review, element: <ReviewPage /> },
           { path: paths.reports, element: <ReportsPage /> },