-- L10b Betrieb & Aufräumen (Aufräumpunkt k, Spec §31 Kostenlimit):
-- Optional monthly AI token budget (input + output tokens of AiGeneration) per tenant.
-- NULL = platform default from env AI_MONTHLY_TOKEN_LIMIT, 0 = unlimited.
-- tenant_settings is already tenant-bound (RLS, TENANT_MODELS) — no new table.

-- AlterTable
ALTER TABLE "tenant_settings" ADD COLUMN     "ai_monthly_token_limit" INTEGER;