ecb6fd4394
Adds GET :id/overview/stats + TeamsService#getOverviewStats, aggregating team-wallet and player payment transactions into a 12-month balanceHistory (cumulative, carry-forward), monthlyFlow (income/expense), and topOutstanding (top 10 active debtors) for the upcoming overview KPI charts. fine/levy/fee and player-level credit are excluded, matching the "Ist-Kasse" cash-flow rule. Replaces the unmodified NestJS-boilerplate placeholder specs for TeamsService/TeamsController (which already failed at baseline) with real tests using the team-access.service.spec.ts direct-construction convention. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>