feat: Recurring invoices + license suspend on dunning level 3 (PRD §6.4/§6.6)

- Recurring API: list contracts needing invoicing + run endpoint
- Auto-generate draft invoices for Wartung/SLA + Dienstvertrag contracts
- Automatic license suspension at dunning level 3 (PRD §6.4)
- Recurring billable expenses tracking
- MRR/ARR computation from contracts + expenses
- Prisma: added Contract.company + Expense.company relations
- Scheduler info (pg-boss monthly cron in production)

src/components/aos/top-bar.tsx

@@ -31,6 +31,7 @@ const TITLES: Record<ViewId, { title: string; crumb: string }> = {
   contracts: { title: 'Verträge', crumb: 'Betrieb / Verträge' },
   expenses: { title: 'Ausgaben', crumb: 'Betrieb / Ausgaben' },
   finance: { title: 'Finanzen', crumb: 'Betrieb / Finanzen' },
+  recurring: { title: 'Wiederkehrende Rechnungen', crumb: 'Betrieb / Wiederkehrend' },
   accounting: { title: 'Buchhaltung', crumb: 'Betrieb / Buchhaltung' },
   audit: { title: 'Audit-Protokoll', crumb: 'Betrieb / Audit' },
   data: { title: 'Datenverwaltung', crumb: 'Betrieb / Daten' },